Many television news stories (particularly during rating sweeps time) take a UV light into hotel rooms to elicit the ewwwwww-yuck response.
But this article in the March 2007 Conde Nast Traveler is really disgusting. I've heard of people taking extra ziptop plastic bags in their luggage so they can bag the TV remote control, and after reading the article that sounds like a good idea :) There's already a commercial version available.
People mock me for using hand sanitizer! Not anymore! I am vindicated! (Just make sure your hand sanitizer has a high enough percentage of alcohol to be effective)