Quick links to some popular online travel booking resources:

TRAVEL PORTALS:
Expedia.com
Hotwire.com
Orbitz.com
Priceline.com

AIRLINES:
Air Canada
Air Tran
Alaska Airlines
American Airlines
British Airways
Continental
Delta
Frontier Airlines
Jet Blue
Lufthansa
Northwest Airlines
Southwest Airlines
United Airlines
US Airways
Virgin Atlantic

CAR RENTALS:
Alamo
Avis
Budget
Dollar
Enterprise
Hertz

CHICAGO PUBLIC TRANSPORTATION:
www.transitchicago.com