Conventional travel itineraries list travel related information, such as flights and hotel bookings, in a chronological order of date and time. As such the only observable relationship between different activities listed on a conventional itinerary is that the activities follow one another sequentially in time. Various graphical travel itinerary visualization systems have recently been developed to allow making references between different events on an itinerary easier. These systems rely on large computer displays for visualization of itinerary information during the pre-travel planning and preparation phase, and allow access to such information using mobile phones during the actual trip when access to a computer with large display may not be possible. We have developed a system called PATI, which allows not only access but also modification of personal travel itinerary information using Personal Digital Assistant type devices. This paper describes PATI and introduces techniques used...