This morning I made a widget for my Windows 7 desktop so I didn't have to load up L4D2 every time I wanted to check the server status. This widget displays the number of players on, the map being played, and the ranking of the server (It should be number 1!).
I took a gametracker banner and turned it into one of the most simple little tools I've made.
Just unzip and install. If you have a mac well... TOO BAD!
UPDATE: Now shows each player who is online as well as a picture of the map being played!