Oh and incase some of you really catch someone trying to break into your computer, here's a useful page (for the lazy):
www.samspade.org It does traceroute and much more.
Best way to get back at someone is to have the log from your firewall, take the IP and run a traceroute and email the offenders ISP. Most, well any serious, ISPs have an abuse email addy.
I did have a guy from Switzerland bothering me for days. He tried to give some stupid trojan, again and again. I sent the logs with all of the info to his ISP. About 6 weeks later I got an email from a nice lady telling me he was no longer with their network. FELT REAL GOOD!
-tek