Most serious travelers carry a folder with printouts of their flight, car and restaurant reservations. With TripIt, you can simply forward all that information to firstname.lastname@example.org, and the website's "itinerator" does the rest. Everything is organized in one place, and the itinerator will fetch weather forecasts and maps, so you'll be totally prepared. The information can be printed, accessed via iPhone and shared with friends. Even cooler, a social-networking feature of TripIt will alert you if you're about to cross paths with a friend who is also signed up with the service. So if you and one of your old buddies happen to have a similar layover, you'll know beforehand and be able to meet up.