You're operating from a base assumption that others may not share: that you need your community to be bigger than the people you can hand your business card to.
what about a microblog here? are there limitations on their size? what are those limits like?
I mean, if the things support markdown and a decent storage space, that sounds like something better than a tweet and a gist combined.
edit: I went and looked a little myself, and it seems microblogs must be posted to a magazine? can't I just publish one from my own user profile or something?