I agree with MM, also I always carry around with me packs of those toilet seat covers and travel-size toilet tissue rolls. I remember the university in Sevilla NEVER having any (they also seldom had soap or paper towels)!!! Those baby wipes are good, and also maybe those new hand sanitizers that they have now (although some people say that they're bad because they force germs to mutate, they kill germs but not bacteria, etc., who knows).
Sometimes you are on a train or bus or metro and SOMETHING smells nasty, so I also carried around scented hand lotion to hold up to my nose or to put on my hands if that happened. Some people's noses are sensitive to lotion though, so I only used this tactic in extreme situations.

[This message has been edited by ilovemadrid (edited 11-03-2000).]