Ask HN: What cool numbers are there to graph online?

Some neat ones I've made:

Stackoverflow questions (linear??) http://webnumbr.com/stackoverflow-questions

My twitter followers http://webnumbr.com/ptarjan-twitter-followers

Wii price on amazon http://webnumbr.com/used-wii

Hackernews top scroe http://webnumbr.com/ycombinator-top-score

And any recommendations for the site are welcome too :)