Ask HN: Best unintended use of your webservice?

[TimH]

I build a website called favstar.fm. Its purpose is to provide feedback on tweets - and easily show who is favoriting and retweeting your tweets.

This morning I woke up to discover a Japanese user has been using it as a canvas. Visit this tweet and click on the 'others' link next to retweets and you'll see a cool picture that they've put together by carefully setting up avatars for over 60 Twitter users, and then making them retweet a tweet in just the right order.

http://favstar.fm/t/30772880274886656

Has your webservice been used for something totally different than what you intended and produced a nice result?

[david927]

Our site, Kongoroo, (http://kongoroo.com) is meant to be something like Reddit for kids sites, but we're noticing that the English language learning sites are popular for visitors from Spanish-speaking countries and China. Teaching kids English is great and we'll extend that usage, but we really didn't expect it.