I like the concept, but I worry about the accuracy for a feat like this. For my results (@jfornear), about 1 in 5 of the recommended follow backs would be considered spam by a human. There were about 26 accounts without pictures that were recommended follow backs, and all 26 were spam or dead accounts.<p>I'm actually working with the Twitter API right now myself and have been meaning to filter out accounts that don't bother to upload their own picture. That might be something you could think about.<p>All (and only) default images are stored on <a href="http://s.twimg.com" rel="nofollow">http://s.twimg.com</a>, I think.