Apple iPhone supports Tibetan input and text, if you are using iOS 4.2 or above, go to Settings -> General -> Keyboard -> International Keyboards -> Tibetan.
The Tibetan keyboard is based on Wylie, but it is not very useful for people who haven't learned Tibetan before.
There are two apps which can be useful for travelers:
English-Tibetan-English Dictionary (free app), no examples, simple word-to-word translation only, but can be useful for basic communication. Amazingly, it's free!
http://itunes.apple.com/us/app/tibetan-dictionary/id418873951?mt=8
Tibetan calendar (also free), maybe helpful for checking out festivals.
http://itunes.apple.com/us/app/tibetan-calendar/id370371782?mt=8