I've seen people put automotive grade stickers on their bikes. A recent bike on Craigslist had the headbadge replaced with a well wearing U of Texas sticker. Those stickers last as long as the riders care to ride the bike, but clearly they aren't as nice lookin' as a 3 dimensional plastic injected item you stick on a car.
Personally, since I went to nationally unknown schools, I prefer something simpler.
