Is it possible to create blogs by category?

Using Buddypress, is it possible to have community members create blogs in categories. So that when you create a blog, you choose what category it falls under?

My first response to this when asked was to use the group feature, create a community blog for each group and allow group members to be contributors on the community blog.
That way you can have multiple contributors to each blog, rather than trying to administer 100's of blogs that are about the same thing...especially if there are only going to be 5 or 6 categories.

What are your opinions?.