Folks,
Report bike thefts to the police. You can not get it back if they do not know it is gone. Know your bikes serial number and info. Serial numbers go on the nationwide network for stolen bikes when reported to the police. Without the serial number your odds of recovery go way down. Register your bike, the police or city will then have all your bikes info when needed and you do not have to try to remember where you put your bikes info. Also independent proof that the bike is yours. In Madison, WI bikes have an eight (8x) times greater chance of recovery if it is registered. Lock your bike when it is not between your legs. Yes, I know it is a pain but 10 seconds putting on a lock beats having to buy a new bike. Put your name and address inside the seat post. That way, hopefully, the bike shop working on your bike will know it is stolen and does not belong to that guy who brought it in to have those clippy things taken off and real pedals put on the bike. And as Bruce said, lock your doors at all times, to many bike are stolen out of unlocked garages and cars. Just a few more thoughts on how to keep your bike yours. Ride safe, be smart, may it feel like it is downhill all the time on your next ride but most of all just ride your bike.
It should also be noted that Lance Armstrong and Team Astana had four bikes stolen at the Amgen Tour of California. Two of the four bikes were recovered, but that still leaves two out there in the mix.
Bruce