Nowadays, I'm looking for a travel manager on iPhone. In Japan, this kind of app is not so popular, but it is so useful for business traveler even you are not so frequent traveler like me.
You could find many apps searching with the word "travel manager" on iTMS. For example, TravelTrak, Worldmate, TripDeck and so on.
Many of them have the functions downloading from TripIt: the most popular travel management service on Internet, some have functions to manage iteneray on iPhone, a few has flight and hotel searching functios from iPhone itself.
After testing some apps, I decided to use TripCase for a while. It has a nice interface, good connectivity with it's own web page, and furthermore wonderful searching functions about flights and hotels.
Very sorry to say, TripCase and it's web site don't issue iCal feed, so that it can't share the information with the iCal on my MacBook Pro. If it had this function, TripCase would be the ultimate travel management app. Sigh....
By the way, which app are you using on iPhone as your travel manager?
