The
Bike Registry or Bike Index (click this) is a website where you can post details, picture and Serial Number of your bike along with your contact info.
Should your bike ever be stolen this helps in two ways.
1. If offered for sale, a lot of buyers will check that the bike Serial # they are about to buy and make sure its not hot.
Nobody really wants to pay good money for stolen property. If caught you'll loose the bike and your money as a minimum.
2. If the police find your bike, they use these registries to reunite it with you.
And all this for the pricey sum of $0 I believe (maybe a donation)
Barry