TripIt

from Lifehacker.com:

TripIt takes all the work out of storing your travel plans in one place. Instead of making you enter all the details like places and times by hand, just forward reservation confirmation emails to TripIt so it can do all that heavy lifting for you. Register for a free account at TripIt and start forwarding travel plan confirmation email messages from "virtually any" online travel site to plans@tripit.com, and the web service will parse out dates, times and locations and generate your itinerary with lots of additional information, like a calendar, photos, weather, maps, online check-in links and even collaboration with fellow travelers. Check out a sample TripIt itinerary that came together by fwd'ing a few emails from online bookings. Now, this is a travel organizer I might actually use (versus just saving all my trip-related messages in my email software.)

TripIt