Using a secure protocol, OAuth, which is an open standard to enable API authorization, users with Gmail and TripIt accounts can log onto TripIt and click an Start Auto Import button to authorize TripIt to import their travel-itinerary confirmations automatically instead of having to email them manually to TripIt.
Read the full story at http://www.tnooz.com/2010/08/11/mobile/tripit-integrates-gmail-google-apps-for-automatic-confirmation-retrieval/