And then what? Though you may have an IP Address there's really nothing you can do with that, only the police can use that information to contact your ISP and get an actual address. Then they must attempt to use that information with the courts to get a warrant which allows them to make a physical search. This level of action by law enforcement is only likely if either your PC is extremely valuable, you have great clout in your community or the lost laptop contained the personal information of many people from a business or government agency.
Just like with malware, the best idea is to protect your laptop itself. Don't leave it unattended in public areas or visible in your car, instead store it in the trunk before reaching your destination. If it's stolen from your home you likely have bigger problems. Most thefts occur because of foolish decisions made by the owner, so simply avoid the common mistakes of assuming that no one will take something from a place you assume is 'safe'. There is no such place.
Bitman