PSA: Smoking is so bad it voids your computer warranty : Christopher Null : Yahoo! Tech:
"Lighting up near your computer is heresy enough that Apple says it voids your warranty should you need to bring a smoke-exposed computer in for repair.
Specifically, in at least two instances in different parts of the country, Apple has voided the warranty and refused to provide repair service on Macintosh computers exposed to environments where cigarette smoke has been present. Calling cigarette smoke residue (tar and whatnot) inside a computer a health risk and a 'biohazard,' in both cases Apple customers have been denied service despite having time left on a valid warranty."