TripIt is a lifesaver for me. I'm sure I'd mess up a lot more than I do if I didn't have an app like TripIt.
My only material beef is that I think it could do a better job of flagging possible oversights in your itinerary. "Umm Dave, I'm afraid you don't seem to have anyplace to stay on Wednesday night."
On complicated trips, I actually print out a calendar grid and make notes by hand. It would be nice if TripIt had a month calendar view that let you look at things that way.
2. Forward booking confirmation to plans@tripit.com.
3. Now all those details are in my calendar.
What’s particularly useful is how it handles time zones. Flights seem to ‘just work’, and in the notes for any appointment it’ll tell you the local arrival & departure times anyway.