Sorry for posting in old threads, I figure I should point out a few nuggets of information about the USO at O'Hare airport.

The USO at O'Hare is open 24 hours a day as long as there is a volunteer on duty, if you have the spare 30-60 minutes, its well worth your time to drop in, grab a bite to eat, fire up your laptop and use the free WiFi, and relax. There is also a big screen TV, a family room, and five recliners if you want a little shut eye.

There is a military line for security in terminals 1, 2, and 3. In terminal 2 (where the USO is) at the center security checkpoint, go to the far right lane, there is a sign that reads AIRPORT EMPLOYEES ONLY and there's a smaller sign that says Military with orders...

Show your military ID and your boarding pass to the TSA officer at checkpoint, and its just like you were in a First Class lane, you can swipe off a whole bunch of time normally spend standing in line.

One more point to consider if you're flying United Airlines, are in uniform, and flying with orders, you can use the United Red Carpet Club.

Hope this helps, have a safe holiday weekend!