It's officially announced, Restaurant Week comes to Chicago the last week of February 2010 (19-28). Try all of those 4 star and out of your price range spots that are on your list and NOT go broke. The great Chicago food blog "Chicago Food Whores" has taken the time to post menus and restaurants. Instead of reinventing the wheel, just go here to read them.
Official Site Chicago Restaurant Week
I posted an update here.