TripIt

I’m definitely going to try this service on my next trip.

“[Once you create an account you can]…forward your travel confirmation emails (airline, hotel, rental car and more) to plans@tripit.com. It doesn't matter where you book, TripIt will "automagically" build an itinerary for you with all of your different travel details in one place, plus maps, weather, and directions.”

http://www.tripit.com/