I finally got a folding bike. A Steyr Cobra in lime-ish green in good shape for $26. As seen here:

http://cgi.ebay.com/ws/eBayISAPI.dll...2504&rd=1&rd=1

It's gonna be a long-term project as I don't really have need of it right now, but new wheels, seat and seatpost, different handlebar setup, caliper brakes, and a more secure lock at the hinge are all in its future.