TripIt works with bookings from the following booking sites:
Agent
* AAA
* Amadeus checkmytrip.com
* American Express Travel
* American Express Centurion Travel
* CheapTickets
* Expedia
* GetThere
* Hotwire
* Hotels.com
* Hotelsdiscounts.com
* makemytrip.com
* Orbitz
* Priceline.com
* Travelocity
* Trondent American Express
Airline
* Air France
* American Airlines
* Alaska Airlines
* Aloha Airlines
* Air Canada
* airTran
* British Airways
* Cape Air
* Cathay Pacific Airways
* Continental
* Delta
* easyJet
* Hawaiian Airlines
* JetBlue
* Lufthansa
* Northwest
* Midwest Airlines
* Ryanair
* Southwest
* Swiss International Airlines
* United Airlines
* US Airways
* Virgin America
* Virgin Atlantic
Hotel
* Best Western
* Cambria Suites
* Choice Hotels
* Clarion
* Comfort Inn
* Comfort Suites
* Crowne Plaza
* Doubletree
* Four Points by Sheraton
* Four Seasons
* Hampton Inn
* Homewood Suites
* Howard Johnson
* Hilton
* Hyatt
* Holiday Inn
* InterContinental Hotels
* La Quinta
* Luxury Collection
* Marriott
* Quality Inn
* Radisson Hotels & Resorts
* Sheraton
* Sleep Inn
* Super 8 Motel
* Travelodge
* Westin
Rental Car
* Alamo
* Avis
* Avis Europe
* Budget
* Dollar
* Hertz
* Thrifty
I emailed them and got a response right back. They're working on lots more, including being able to read in most PNRs and those Amadeus-style text files that my travel agent always attaches to an email.