I haven't seen much of this around, and I'm not a network expert/sysadmin, so I need some advice. I have a laptop that I'd like to "protect" against theft (this is really a game more than a real security system to be honest, but it's fun to learn that way :) ):
It's pretty easy to configure postfix to send emails using a gmail account, and it's easy as well to write a cron task at the system level to send emails periodically with arbitrary contents.
If the laptop is connected to the Internet, what are the most useful network (or other?) information that I could send by e-mail to potentially locate the computer? How to get them, and how to format them to be sent by email?