Two years ago I wrote http://formula1db.com , to teach myself sql. To get the data, I had to screen scrape formula1.com . Once I had the data, learning SQL became a joy. I haven't done much with the data since I built the site, but I am considering open sourcing it.
What I don't understand is, why don't sport leagues open source their data. What do they lose? Its a good think that people are so excited about your sport, that they build custom apps based on it. Sadly sport leagues don't seem to get it, I remember the MLB cracking down on a fan generated datatbase of baseball statistics a while ago.