Hello - just wanted to add that the CTA one day pass is the way to go. The only problem I can think of is I'm not sure they sell them at the Midway Orange line station. [CTA website says you can buy a one-day pass there. http://www.transitchicago.com/travel...ines.aspx#pass ]

It is probably about 30 mins to downtown, and if you were to get off at Adams/Wabash, you'd be one block from the Art Institute, a few more blocks to Millennium Park, and very close to the Lake Front trail.

If it's a niceish day, I highly recommend the Wendella Boat architecture tours. You can see all the important buildings, and there's tours that go on the river or into Lake Michigan. There's also a combined one, but that takes a few hours, I think.

Also, in no way do I want to belittle it, but I don't think Navy Pier is anything too special. It's expensive and mostly chain restaurants. The Ferris Wheel is nice, though.

Those are some of my recommendations off the top of my head - hope you have fun!