The Seneca Hotel's website may reflect that they are fully booked for the nights of the 21st and 22nd, but I just called, and they still have some availability, so try calling (1 (800) 800-6261).
Other places with availability are:
Howard Johnson Hotel downtown, rates quoted at $184/night
http://www.hojo.com/HowardJohnson/control/home
Travelodge Hotel downtown, rates quoted at $149/night
http://www.travelodge.com/Travelodge/control/Booking/property_info?propertyId=10073&brandInfo=TL
Also, I've heard good things about Priceline for booking Chicago rooms on busy weekends. http://www.priceline.com/
Added by Sarah on Fri, Apr 18th 2008
Hello all! Here's some hotel information. Please book soon, rooms tend to fill up fast during Chicago's summer convention season.
Jeff and I have reserved a block of rooms at the Sleep Inn, which is close to the Midway Airport, about a 25 minute drive from down town Chicago. The rate there is $134/night plus tax.
A number of hotels couldn't give us wedding blocks, but told us that they still have availability (as of the date of this post) and would be happy to take reservations directly. One is the Congress Park Plaza, which is on Michigan Avenue across from Grant Park. The rate should be about $200/night plus tax. Another is the Seneca Hotel, which is close to our wedding venue on the near north side of Chicago. Rooms should run around $180/night. Another is the Inn at Lincoln Park which is a more casual place not far from our venue. The rate there should be around $124/night.
Lastly, for more cost effective accomodations, check out Lonely Planet's list of Chicago motels and hostels: http://www.lonelyplanet.com/worldguide/usa/chicago/where-to-sleep?ec_s_name=asc
Sleep Inn Midway (ask for Terman/Link wedding block)
6650 S. Cicero Ave.
Bedford Park, IL 60638
(708) 594-0001
Congress Park Plaza
520 S. Michigan Ave.
(312) 427-3800
http://www.congressplazahotel.com/accommodations.htm
Seneca Hotel
200 E. Chesnut St.
1 (800) 800-6261
http://www.senecahotel.com/guestrooms.htm
Inn at Lincoln Park
606 W. Diversy Parkway
(866)774-PARK
Added by Sarah on Sat, Apr 12th 2008