Adeona from University of Washington provides an open source, free and completely non-proprietary way to track your stolen laptop. No 3rd party servers are required, only a small client needs to be installed on the laptop !! The software is available for Windows XP, Mac OS X, and Linux! Only the Mac OS X version takes pictures right now, but I am sure that the Windows and Linux versions will catch up eventually. But at least you can have your laptop send to you its IP hookups, and nearby routers, and any wireless access point that it used. While it may be frustrating to watch your laptop travel, when you can not, just the knowledge that your personal machine can be tracked may give you that extra quiet moment.
The uses keep on coming, for if you install this client on your companies desktops, and they are stolen, and the OS is not wiped then you can track them as well!
For complete security you want to encrypt your system then use True Crypt as I have discussed before in this blog. Now with version 6.0 a Windows Vista, XP and 2k are supported, as well Mac OSX and Linux. There is even a procedure to encrypt USB flashdrives now !! If that was not enough TrueCrypt 6.0a has a hidden operating system feature so that you can make it look like you have given a good password to use on you system, but in fact the actual data is still actually hidden and unusable by who ever is holding you or your system for ransom! Just look at the FAQ about Hidden Volumes.