I think it would be cool to have a little Facebook application which would give you key stats from your cPanel or other web-server. It could give statistics on things like: disk space, bandwidth and access hits for every day over the last week; just a basic summary. It would also of course give you links to key areas in cPanel like email management etc.
Just looking up
There is a very basic one now, called Server Monitor, but it basically just shows if your server is up/down, and some basic stats on up-time.