I have to disagree with George Dorn's statement that GHB is easy to taste (though I thoroughly agree with the title and concept of the node and everything else he said). I've done GHB recreationally twice. The first time I did it, I dosed twice, once by mixing a 1.75 cc dose in a 12 oz can of Nestea Cool, once by mixing .25 cc in a small cup (~ 4-5 oz.) of Mountain Dew. The second time, I did 2.25 cc, mixed in < 12 oz of Coca-Cola, and still couldn't taste it. These are normal recreational doses (and provide a lot of fun, assuming you like to use alcohol recreationally). Considering that nowadays, the vast majority of GHB is manufactured illicitly, the quality, impurities, and forms can vary widely. Both of my experiences were from the same batch, and I have to say, I would've never known something was up if that GHB had been slipped into my drink, especially if I was already somewhat drunk. This means that when you're in public, you should always have a close eye on your drink, and when you voluntarily do a drug you've never done, you should know the possible reprecussions. That's just responsible drug use. This is also not to say that an unattentive person who gets dosed unknowingly is responsible for their own rape. Just that GHB's status as a date rape drug isn't really based on its taste or lack thereof. Let's not forget that alcohol is by far the most often used date rape drug. Not to mention that if you want to spike someone's drink without them knowing, the totally legal Everclear is a great start, as pure alcohol has no taste whatsoever. Can't tell it's there till it burns, and it takes a lot of Everclear to feel that burn (I've also had my share of Everclear punch).

Update (Jan 15, 2006):
Randombit messaged me to dispute my statement that alcohol is the most used date rape drug. I didn't mean to say that this is done by spiking drinks with Everclear (although I see how my statements were confusing, since I did actually say that as well). What I meant was more along the lines of 2006 New Scientist article titled "Alcohol, not drugs, poses biggest date rape risk" (http://www.newscientist.com/channel/health/mg18925334.400, and i'll ignore the implied contention that alcohol isn't a drug, since that's not the point of this node). Anyway, I was making two separate but related statements. The first is that alcohol is the most used date rape drug, in the sense that feeding someone drinks (which they voluntarily consume) so as to impair their judgement is the most common method of date rape. The second point was that alcohol has no taste of it's own, and so could be used to augment the alcohol content of an existing drink. It would not be possible to do this in one dose as it would with GHB (since that concentration of alcohol would most likely burn quite a bit), but the augmented alcohol content could certainly add up over the course of a night of drinking. I did not mean to imply, e.g., that grain alcohol could easily be substituted for water.