The 2007 WADA list has caffeine in the "2007 Monitoring Program" but it is not a "Prohibited Substance". The 2007 US AntiDopingAgency (USADA) list seems to directly quote the WADA list on stimulants, so ditto. It used to be one of the threshold substances (under 12 micrograms/ml of urine and you were OK) but was delisted as of Jan 1, 2004.
HA! I just noticed this draft from 11/30/07! Dang if I can remember where I was going with it, just a stub and all. Reminded me about something over at Zuska's diggity dogs. Caffeine really is a drug. Gee ya think?
no longer quite the n00b scicurious recently had something about adenosine and caffeine so I'll just point you there for the science.
one of PalMD's podcasts ( I think it was #2 or #4 but I could be wrong) talked about the wonders of coffee and how medicine can't really find much to worry about. Sure, save the addiction part.
Anyway, I'll just snap this up in case it jogs my memory of what I was thinking about. Probably some papers on cycling performance I guess....