When it comes to random drug testing, hair knows a lot more than urine or saliva tests can tell ya. According to the New York Times, hair samples can indicate drug use up to 90 days earlier. Urine and saliva tests can't pass that test. Workers may lie about what they do after business hours (and some argue what they do after business hours is, well, their own damn business), but their hairdos tell another story. Of course quickly following in the heels of the new hair tests are hair follicle concealing shampoos that allegedly get you through a drug test. These shampoos join a cottage marketplace for tampering with workplace drug tests with a variety of pee potions, powdered urine and saliva-altering pills. They also offer tests not related to drug use -- such as the Infidelity Test.