Jeff Vilimek did an awesome job of summing up a good number of the Midwest (IL, IN and WI) district user groups.  Some are more Microsoft focused, some are more technology and platform agnostic.  Check out his blog for detailed descriptions of each of the groups!  I am going to siuggest a few more since this seems to be more Chicago based.

Here is the short summary of what he has so far:

Midwest Developer Technology User Groups