Two weeks ago I wished I knew how quickly the watcher count on some of my repos was growing. Now I can. In addition to watchers, I'm also tracking issues, forks, and repo size.
I find it fascinating to watch how issues trickle in throughout the day for large project like Rails http://bit.ly/rvsNLM. Also interesting to see how Node seems to be rapidly growing in size http://bit.ly/vstVN9.
Let me know what you think http://gitego.com/
EDIT: Just found the link on the graph. Tough find :P