I don't know how long of rides you are looking to do, but I live in minneapolis, and I am always up for a new riding partner... Perhaps we could get a posse going? Do some single speed "marathons".

I did the St. Paul classic last fall on my single speed with a 46/18 ratio, and was leading the pack most of the time. I think for the 31 miles ride, I finished in 1 hour 26 min or something like that, average was over 21mph, decent considering there was some hills to contend with...

I do think the twin cities is a good place for cycling, lots of trails all over the place...