I have a crack in the chainstay of my Giant Defy Composite 3. I don't know much about carbon repair, but poking around ST threads I found the companies listed below. None is in the Chicago area. If possible, I'd rather not ship my bike and I figure the fact that I live in a large urban area increases my odds of a local repair. If you know of a reputable place in the Chicago area, I'd appreciate it.

http://calfeedesign.com/

http://brokencarbon.com/index.html

http://rrvelo.com/repairs.html