Does anyone have any experience with "laptop calling home" software. Software that sends email to your own address or to a web server with information of the whereabouts of your laptop? This way a lost or stolen laptop can be retrieved easier.

I've looked at http://adeona.cs.washington.edu/ This one currently doesn't work since they don't have a server.
I am also trying to get this one to work: http://preyproject.com, but a sever lack of documentation keeps me from getting it to run