Took a stroll down Navy Pier - Chicago. Walking and taking in the beautiful view is completely free - individual exhibits cost, but completely worthwhile just to watch the boats in the harbor and the people (of course!).
The perfect 3-day Chicago itinerary for first-time visitors. This guide covers the top attractions in the city, including the Cloud Gate in Millennium Park (aka the bean) http://www.mintnotion.com/travel/3-day-chicago-itinerary/