well, one of my favorite "freebies" in Chicago is at Ghiradellis...you will get a free sample of chocolate just for coming in! It is not far if you do visit Navy Pier, certainly walkable. You can also pop into the Hershey factory,
Disney Store, just walking about is kinda fun. There are usually "living statue" entertainment here/there...just keep you eyes open. What time in the summer? Taste of Chicago's dates have been altered I think....or is you are coming mid/late August the air show is then, it is awesome and free, but very crowded! I would try Navy Pier for sure, there is a McDonalds there which is going to be your most economical food choice or you can pack a lunch. If you park at the pier I believe it is about $20 for the day, may be higher, but there are usually bands playing for free, some boardwalk type entertainers and every Wed and Saturday nights you can see fireworks ( unless they are cutting back due to budget as mentioned) yes, the childrens museum has a fee, and I think it is fairly high, as in I would go to the Museum of Science and Industry and pay there. If you want an inexpensive side option, you can take a water taxi along the river, I think it is about $2-4 per person each way ( and there is a r/t rate as well) but it fun to get from point A-B and then walk back or whatever. If you can. book a hotel with an indoor pool, weather can be iffy with some cooler days or rainy, so having an indoor option may help that and if you are paying for a hotel, may as well get use out of it! You can pack decent kites and fly those by the lake, in grant park etc., Chicago generally has enough wind to accomodate that daily,

bring rollerblades and skate along the path along the lake, it is reallly pretty on a sunny day. Your teens will like Oak Street or North Avenue beaches..., If you can swing it, heading up into the Sears Tower for the ledge is awesome...we waited 2.5 hours to go up for the cheap rate (just have stuff to entertain the younger ones like hand held games etc) once you are up there you can stay as long as you like...it is really very cool to do. A less expensive option is the Hancock viewing,closer to Navy Pier. While I know it is a pain to lug a cooler around etc, having snacks/water bottle is going to save you some $ each day. I hope you enjoy your vsit to our city, summer is the best time to visit Chicago!
