I currently still use the foam case the P4 comes in while traveling around. I'm in search of a case that would be easier to carry with me on my travels where I'm looking to fly. For example, I will be taking a trip to Michigan's Upper Peninsula here in a few weeks and will be doing a lot of hiking which draws me to a backpack case... however they all seem rather expensive... Anyone have any experience with a more mobile case? Any information would be appreciated.