If your going todo a lot of world travel you may consider picking up one of these bags. Northface makes a relatively in-expensive backpack/duffle that has served me well on many world trips. Its a waterproof, lightweight, backpack or duffle, carry on size, do it all bag. It has loops so you can strap it to the roof of a cab or bus. Fits perfect for all carry on requirements and protects your gear from all the elements that can be thrown at you.