An essential vitamin, without which one suffers from headaches, depression, sudden violent anger, sluggishness, muddled thinking, and crankiness.
I once went 10 months withoutvitamin C and only suffered a mild bout with scurvy and tooth loss...I went 24 hours without caffeine and that's why I'm doing life without parole.
A wonderful stimulant and vitamin that is an essential part of everyday life for those who would like to avoid sleep, or just be generally more productive. Diety, ritual, and drug rolled into one.
Caffeine.
Bawls, coffee, jolt, some teas, jolt gum, mountain dew, diet coke, amp, red bull, etc.
ThinkGeek.com sells a lot of alternative sources, but then again, 7-11 does too.