Some poker players have been talking about this one too to boost their performance.

http://articles.latimes.com/2007/dec/20/science/sci-braindop...

http://groanblog.livejournal.com/865.html

I've read elsewhere that it can be addictive.

Also, the LA Time article discusses Inderal, a beta-blocker which could be considered a smart drug since it eases nerves by reducing adrenaline rushes (no more shaky hands or pounding heart). Might be helpful to the hacker community if you're stricken by nerves working on a tight deadline.