Poll: Do you smoke marijuana? 17 years ago
anonymously for obvious reasons:
Echoing someone above, I'm fairly sure smoking weed has dulled the edge of my intelligence more or less permanently. On the other hand, I think it's probably made me a much nicer, well-rounded, and balanced person. I've no regrets.
But I never found it expanded my mind - just made me relaxed and happy. Personally, I find hallucinogens/entheogens much more conducive to hack-like tasks.