From ArborWiki

http://coffeehousecoders.org/

Whether you're new to coding or a seasoned hacker, you've got your own pet project, or you want to check out what other people are doing, coffeehousecoders is for you. We meet once a week to bang out code, swap code snippets, talk about the latest and greatest in software, and bounce around ideas.

The group meets in Ann Arbor on Wednesday nights; there is an east side group as well that has met at 14 Mile and I-75.