Phorp (Phone Home Robot Pro)
Open source for Windows/Mac/*nix/etc. Comes with precompiled Windows binary.
WHAT IS PHORP?
Phone Home Robot Pro (phorp) is an open source program that runs on your pc or laptop, and periodically "phones home" to a server somewhere to check if it has been stolen, and gets instructions on what to do if it has been.
There are a lot of services you can buy that perform similarly to phorp, in that they connect regularly to a central server so that you can hopefully track them down when they are stolen. In general, phorp is different from these services in that it attempts to be extremely lightweight and minimalistic, and in that there is no single service you need to subscribe to. Instead, you can use your own web servers or ftp accounts as the home page for the program to phone home to and for you to leave instructions for.
NOTE: This is an advanced tool for advanced users; it requires some reading and work to set up.
Read more and download..