I'm part of an established indie pop band and we have a lot of exciting plans in the works, though our drummer recently backed out on us. I've hit up craigslist, Facebook, networked with friends, and I'm dabbling in reddit and Drummerworld. Have I missed any other forums or other places where I could find a drummer in Chicago? (If you happen to be interested, PM me for details.)

Any advice would be appreciated!
Try DrumChat and Drummerworld's forum

I'd say the latter is more realistic however try both. Best of luck man!
If any music stores in the area have a board for posting up flyers, put something up there.
Gear: Gibson Les Paul Studio, Gibson SG Special, Fender Stratocaster, Fender Telecaster, Fender Jazzmaster, Gretsch Pro Jet, Carvin C350, Epiphone ES-339 P90, Epiphone ES-335 Pro. Peavey 6505, Sovtek MIG-100, Vox AC30, Peavey XXX.