welcome to chicago.
Did they collect $200 when you arrived? If not, just paypal me.

There is a nice race series in effect right now that you might want to investigate:
http://www.bikeforums.net/showthread...&highlight=tdc
and sure to be more!
Group rides also get posted here frequently, so keep you eyes peeled.

as far as the Critical Mass rides - no clue. I avoid them.