Allow categorizing or tagging of repositories

I love that BitBucket lets me upload unlimited repositories, but presently they all show up in one big list, and it's difficult to browse them all. It'd be awesome if it were possible to tag (not to be confused with Mercurial tags) or categorize repositories and browse and filter these tags.

Some tags could even come from metadata, such as which language the repository is in - a page where I could see all my Java projects would be very useful, for instance.