Potentially relevant - Johann Hari's article in HuffPost about his experiment with Provigil (aka Modafinil).
http://www.huffingtonpost.com/johann-hari/my-experiment-with...
http://www.huffingtonpost.com/johann-hari/my-experiment-with...
http://en.wikipedia.org/wiki/Johann_Hari#Journalistic_contro...
(For Americans - Hari is like the British Jayson Blair).
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.
It's a lovely little thing though, very nice clean focused sensation coupled with a lack of tiredness.
It's probably not addictive, but what if you become addicted to the lifestyle it makes possible?
Steroids are considered psychologically addictive for this reason.