Adeona periodically records the internal, external IP addresses and names of nearby wireless base stations to a distributed file system. On Macs, it will also record a small snapshot using the built-in camera. All of the data that it records is encrypted, so only the person who has the private key and password for the key can obtain it.
If your computer gets stolen, you can retrieve this information using your backup copy of the private key/password. If you pass that information on to local law enforcement, you'll have a much better chance of getting your computer back.
Finally, make backups, especially if your data is worth more to you than your hardware. Apple's Time Machine is the easiest to use backup system i've ever seen. Buy a quality external drive that has at least 2x the capacity of your current disk, tell Time Machine what disk to use, then plug the disk in daily. If plugging in is too onerous, get Apple's Time Capsule hardware for wireless backups. Backups have never been so easy and inexpensive (in 2001 I worked with my first > Terabyte device, a Netapp F840. It was enormous and extremely pricey. It took up one entire rack, used 168 very expensive power hungry 18 GB disks, and backups of it were handled on a 40 gig DLT tape robot. Today you can buy the equivalent amount of storage for the monthly electricity bill of that Netapp F840). For linux and other unix systems I recommend rdiff-backup for simple incremental backups.