http://thelocaltourist.com/freethingstodoinchicago

http://www.eventbrite.com/directory?loc=Chicago%2C+Illinois&is_miles=True&city=Chicago&vp_ne_lat=42.0231&slat=41.88&vp_sw_lng=-87.9403&cat=social&slng=-87.63&date=weekend&vp_sw_lat=41.6443&radius=60.0&vp_ne_lng=-87.524&lat=41.88&lng=-87.63

 

http://www.chicagoenvironment.org/events/index.cfm?PageNum=2