Obviously, your best bet is to be drug free at the time of the test.
I would recommend two months of drug abstinence before the drug test.
Drug retention periods are as follows: 
Compound                       Approx. Retention
Amphetamines                   20-25 days
Barbituates                    10-14 days
Cocaine                        2-4 days
Ethyl Alcohol                  1-2 days
LSD                            20-40 days
Marijuana                      14-30 days
Methaqualone                   14-21 days
Opiates                        10-14 days
Phenocyclidine (PCP)           10-14 days 
Note: Length of retention varies because of many factors, including 
bodyweight, metabolism, body fat ratio, and the quantity and concentration
of the drug.    Given the above information, you may find yourself in need 
of a way tobeat drug testing other than 2 months of abstinence.  First off, 
wateris your best friend.  Drink a LOT of it.  Secondly, purge your system. 
Urinate as often as you can before the actual test.  The first urine
of the day contains the highest concentration of contaminant particles.
Some people can't "go" with someone watching.  The testers, to speed 
upexcretion, might encourage you to drink as much water as you can.  
DO IT!Thirdly, adjust your sleep cycle.  Getting up earlier will let you 
squeezein more trips to the bathroom before the test.  If necessary, 
stay up allnight and drink water.  Fourthly, use your glands.  A good sauna 
flushesout impurities through sweat.  THC and other metabolites are 
retainedin fatty tissues.  Any exercise to reduce body fat may help 
you beatthe test.   Intense watering does not hide the presence of any 
illicit substance.You are aiming to dilute all traces to a level below 
the cutoff pointneeded for a positive result.  This is mandatory, elementary 
defense. The Consent Form:   To protect themselves from lawsuits, testers 
will ask you to sign aurinalysis consent form.  It will ask you to list the 
drugs you've takenin the past week.  Cross out the word "week" and write 
in "month."  Ifthe supervisor screams at you, just tell him you read an 
article thatsaid an over-the-counter drug you took for the flu three weeks 
ago couldshow up.  Now for the drugs.  For almost every illegal drug there 
is anOTC drug that tests positive.  Here is a list of cross-reacting drugs 
thatyou should list on the consent form: 
Drug/Metabolite              Cross-Reactive
Amphetetamine                OTC cold medicines, such as Nyquil,                             
Vicks Nasal Spray, Sudafed, Neosynephren, etc.
Barbiturate                  Rarely prescribed compounds... you're hosed
Cannaboids                   Ibuprofen (Advil, Nuprin, Motrin, Mydol)
Cocaine                      Amoxicillin (unconfirmed)
Methaqualone                 None reported to date
Morphine                     Codeine (in any prescription form)  Poppy seeds
Doxylamine                   OTC antihistamines and sleeping pills
Phencyclidine (PCP)          Dextromethororphan (found in some                             
prescription cough medicines)                             Diazepam (Valium)
LSD                          None reported to date 
The Testing Procedure:    Learn what test is being used.  There are three 
that are quitecommon.  The EMIT, Abuscreen (RIA), and ToxiLab (TLC).  If you 
find outthatthey are doing Gas-Chromatography/Mass-Spectrometry (GC/MS), 
then youare totally screwed.  The GC/MS is the chemical equivalent of finding
a needle in a haystack.  It finds EVERYTHING and is IMPOSSIBLE to cheaton.  
Fortunately, GC/MS is VERY expensive, and it is only used forconfirmation 
tests.  Don't worry about it.   The EMIT test does NOT scan for LSD, RIA doe
s.  If you use ethylalcohol or barbituates, RIA does not scan for them, 
but EMIT does.Also, nothing currently scans for Ecstasy, Psylocybin, 
mescaline,or nicotine.   If you are in the military, you are going to be 
tested with RIA.The majority of federal agencies screen with EMIT.  
Private sectorcompanies split between EMIT and TLC.  No problem.... all are 
aboutequally beatable. Slight of Hand:    Something like 5% of the public 
finds it impossible to urinate withsomebody nearby.  More find it difficult 
to void under direct observation.It's a documented medical condition, 
known as "blushing kidneys."Although a minority are afflicted, who is to 
say you're not one of them?A doctor's note or plaintive insistence of 
"Please, I can't do it if you'rewatching" will do wonders for insuring 
privacy.   Be creative when you're in the bathroom.  Use your body to 
disruptline-of-sight observance.  Hand placement can conceal a lot of 
activity,but block with anything else that's available.  Males might say 
they onlyurinate sitting down.  Like a good magician, distract the observer.  
Askthem to run the faucet; say that the sound of running water coaxes 
yourown activity.  Practice, practice, practice!   Observers, though they 
may not show it, are embarrassed as you are.The longer you take to urinate, 
the longer the line behind you grows.Apply enough pressure and they'll give 
you the latitude you need toperform your little alchemy.   Why all the 
contortion?  Because you want to make some subtlesubstitutions, 
replacing your urine with clean stuff. Warm and Dry:    Assume a temperature 
reading will be taken from the specimen.  Don'tswap an ice-cold brew for 
tepid pee.  The standard temperature thatthey're looking for is between 
90.5 and 99.8 degrees Fahrenheit.   Getting pure urine is the first step to 
making an effectivesubstitution.  Know your source.  A relative, a minister, 
an infant,anyone that can be counted on for "clean" urine should be tapped.
The sample should be as fresh as possible.  If you need to keep it a few
days before the switcheroo, stick it in the refrigerator.  After a two
month period of drug abstinence, you can make your own samples galore
and freeze them indefinitely in plastic baggies until needed.   
WARNING!!  Do not substitute animal urine, or make urine from food
coloring and water.  They are easily detected. Houdini in the Washroom:    
The substitute urine is clean and warm.  Now you need a device to
get it into the bathroom.  At a pharmacy, purchase a Bard Dispoz-a-Bag
Drainage Bag or other similar product made for temporary use by
ambulant patients.  Cost, under $4.00.  They come in different sizes.
In our trials, the large leg bag worked best because the extra volume
and shape allowed for a flatter distribution along the midsection where
you'll be wearing it.  It has a short tube and cap, but you can add a short
piece of rubber tubing and a valve for easy filling.    When a test is 
imminent, fill and seal the bag with clean urine.Squeeze all of the air out, 
seal, and put it on - remembering thatit can't withstand more than eighteen 
hours at room temperature.So if the test doesn't go down, take the bag home 
and put it back inthe fridge or freezer.  You can repeat this as many times 
as needed.   Here's the correct procedure for concealing the bag.  
Pull downyour skirt or pants.  Secure the bag to your abdomen, exposing 
as muchof the latex to your skin as possible.  The more surface area 
taken up,the flatter the bag will lie, and the better concealed it will be.
Using the abdomen, not the leg, will let gravity do its thing.  Tape
it in place.  If you don't want to tape it to your body, it might rest
easy if you wear panties or jockey shorts.  Women shouldn't push it inside
panty hose because when you take them off to pee, it'll fall out, unless
you cut a pee hole for the hose.  You can also purchase incontinence pants
for about ten dollars.  These give a firm fit, additional warmth, and
need no tape.  If you need, buy a spool of surgical tape.   Now, snake 
the output tube from the bag to your crotch.  The tubeand the on/off cap 
should be within easy reach, but hidden from sight.It should also feel 
comfortable - strange at first, but comfortable.After a few hours, you'll 
forget about it.  When the time comes for youto "urinate", discreetly 
reach into your clothing, locate and turn onthe release valve, or take 
off the cap.  The "clean" urine will emptyinto the jar, apparently your 
own product.  When the bag is empty, oryou feel you have given enough, 
turn off the supply, zip up, shake yourread end, and smile.  A few drops 
on your shoe or the seat adds a measureof authenticity.   This method works 
well for two reasons.  First, urine observers areon the outlook for bulk 
- glass jars, things concealed in pockets, andso forth.  While someone 
will occasionally ask you to remove a coat,frisks and strip searches are 
verboten.  And someone would have to getawfully close to see the small hose 
at work.  Men standing with theirbacks to the observers and women sitting 
with their skirts up areshields enough.  The drainage bag is form-fitting, 
especially whentaped flat.  No one but you knows it's there.  Second, your
abdomen serves as a heating pad, radiating body warmth directly
to the sample.  In an hour the bag will be near enough to body
temperature.   As good as the bag trick is, it may not be right for everyone.
A good variation.  Purchase a few reservoir-tipped condoms (non-lubricated, 
please).  Fill one, pull a second over it (to preventbursts), and tape it 
as close to your crotch as possible.  When thetime comes to urinate, with 
a presharpened fingernail, puncture thereservoir tip, and go with the flow.
    Women have an anatomical advantage, the option of inserting a
urine-filled condom within the vagina.  Again, use sharpened
fingernails or a concealed pin to get things flowing.  Even at extra-close 
range, it's virtually impossible to tell the source of the yellowstream.  
These techniques should be tried and perfected at home.  Novices
should use water in their dry runs. Dilution:    Diluting urine in the 
specimen jar is invariably more effective thandiluting it in your bladder.  
In fact, dilution was so rampant thatEdwin Meese ordered all federal toilets 
filled with blue dye beforea urinalysis.  The toilet was one source of 
dilution the urine copshadn't thought of earlier.   If a surprise urinalysis 
is forced on you, don't panic.  You're inluck if you're looking into clear 
water.  Dip the specimen cup andfill half full of toilet water.  
Dry the outside.  Fill the rest withyour own urine and shake.  
Rub the jar with your hands to warm.Presto, the sample should be 
dilute enough to fall below the cutoffpoint.   Complete privacy means 
opportunity galore.  Rinse and fill thespecimen jar with hot water to 
increase the temperature; then dumpit clean.  Never use scalding water, 
since that may put it outsidethe acceptable temperature range and could 
even crack a thick,cold container.  Don't be alarmed if you don't have a 
thermometer.Your finger is a reliable dipstick.   Although the Health and 
Human Services Administration insiststhat toilets be dyed blue, low-level 
sources inside government washrooms assure us that in most cases the dye is 
dumped onlyin the bowl, leaving you fresh, clear water in the tank.  Avail
yourself of the porcelain oasis.  But be careful - removing thetank-top 
makes a lot of noise.  And don't flush if you are orderednot to.  
the thin copper or plastic spout in the tank contains freshwater.  
Push down on the big float to activate the fresh-water spout.Avail yourself.  
Take that, Blue Water Meanies!   If you're a moderate drug user, or your 
last use wasn't last night,as little as one third cup of water can make all 
the difference betweennegative and positive results.  Conceal water in your 
mouth, in a rubberbetween your legs or under your arms.  Be resourceful.  
Don't use spit!Saliva contains some tell-tale metabolites. Color Bias:    
Although the color of urine varies from person to person and hour
to hour (depending on diet, metabolism, etc., it is nearly always
yellow), there is an unconscious Enforcer bias that rich yellow urine
is the real thing.  Dilution diminishes the color, so it's
semi-important to compensate.  No problem.  Taking vitamin C capsules
will give your urine a darker shade of yellow.  When you then dilute it,
it will balance back to innocent mellow yellow.  The vitamins increase
the odor, which also compensates for the added water. Chemical Additives:    
Three tablespoons of iodized salt dumped into the sample and
quickly stirred will deceive EMIT tests for ALL substances.  The
salt, and electrolyte, increases the conductivity of the specimen,
and makes it harder for the binding reagents to find their target
metabolites.  Just make sure all of the salt goes into solution.
There's nothing more incriminating than a small pile of insoluble
salt at the bottom of the jar.  One quarter cup of hydrogen peroxide
will also work, as will 3-4 tablespoons of concentrated ammonia or
chlorine bleach.  That about does it.  This information all came from 
the book"Steal this Urine Test" by Abbie Hoffman.  I highly recommend this
book for further details.  While I provided the majority of the
"how to beat the test" type info, he goes into the legality of
drug testing, etc.  Best of luck beating the bladder cops!                                                        
<^> Rostaman <^>