The Internet just beer'd you.
Like a sudsy IMDB, the just-launched Chicago version of BeerMenus.com is a meticulously-organized index of 1,100 beers sold locally, each conveniently cross-referenced with 76 Chicago bars and restaurants that carry them.
Simply hit the site to search where specific beer brands are sold (e.g., Allagash Curieux is served at Fiddlehead Cafe, Prairie Moon, and Rootstock), or select a bar/restaurant to discover what they serve -- for example, The Bad Apple has 17 brews on tap, 62 bottles, and two cans.
The site was developed by two New York-based brothers who've been homebrewing (and no doubt pleasantly buzzing) since the age of 13.
BeerMenus also lists beer-centric events in Chicagoland.
So get out there. Get drinking.
