The release of the first official native iPhone app from the creators of the Tripit web site makes for the ideal traveling companion. And best of all, it’s free.

Here’s a quick summary of this service: In a nutshell, Tripit is a travel planning app that builds interactive itineraries for you that go way beyond the simple chronological action lists provided by similar services. Tripit’s itineraries are filled with extra goodies like integrated maps and driving directions, weather, local sightseeing spots, recommended restaurants, and so on. All of this is contained into a single master itinerary that can be easily accessed from web or mobile, and shared with your network of friends.

However, in order to use the mobile web site with your iPhone meant you had to be online. The Tripit iPhone app allows you to access your itineraries online, offline, or in airplane mode, making it even more useful, even in places where you can’t access the internet.