i would always suggest u to carry your iphone with u wherever u travel. it makes your travel so much more convenient and helpful. the gps, navigation, any local information u need, language translator; iphone can get u all of that.
also the local travelling applications in different coutries makes your travel soo much more convenient. for example when i went to india last year to manali, my travel operator suggested me to download -snip-
imagine how convinient it got for me. and u can always keep ur iphone in your jeans pocket. it is not very uncomfortable and very safe. or u can simply keep it in your waist pouch if you are not travelling in crowded places.
have fun and keep using your iphone!
[ Edit: Snipping what seems to be a disguised promo... ]