The Mercier Nano from Bikes Direct is a nice ride. There's 2 threads in the forums dedicated to it. It may my fold, but it's sweet!

http://www.bikeforums.net/folding-bi...velo-back.html

http://www.bikeforums.net/folding-bi...t=Mercier+Nano

Did you also consider the Respect Cycles Urban Velo? It's a single speed that can easily be upgraded to an internal geared hub. Or, keep it simple and stay SS.

Respect Cycles, Innovative bikes, for The Urban Environment.