Originally Posted by
Jack Napier
If it's on LH, you will probably have access to the FCL, which would be the absolute MUST!
If the OP is indeed flying on LH F to ORD, a visit to the FCL is recommended. Arriving from ROM you can enter the FCL on Level G (Schengen), go upstairs to the integrated passport control within the lounge and exit on Level H (non-Schengen). The most civilised passport control I've come across (although as you are leaving Schengen there isn't much formality anyway).
Here are some
photos of the Munich FCL on flickr.