one of the best aspects of mashups are the way that collective intelligence can be leveraged to add meaning to web-based media. overstream is a web-based subtitle tool for youtube videos that allows anyone to contribute captions for existing videos. this has a lot of significance for the hearing impaired, as well as anyone who doesn’t speak english. this kind of layered media is a good way to enrich media without obstructing the original content. maybe one day this can be built into a browser – a kind of social lens that shows you the world wide web through someone else’s eyes.