Originally Posted by
balima
Why not get off on Washington, walk straight east. Check out Millineum Park with the Bean, fountains, walk along the bridge to the lake front. Enjoy the view and return.
Agree with this. ^
After Mil Park and the the Lakefront, the OP could walk back towards Mich Ave and stop at Tavern at the Park for dinner (on Randolph and Mich Ave - north edge of Millennium Park), then take a nice walk up Mich Ave, and end the night with a drink or two in the River North or Gold Coast neighborhoods.
And while I'd train down to the Loop, I'd probably spring for a cab back to the hotel after a long day of flying and sightseeing. (Approx $40).