I went to this event today where the food coop was giving out free food. They had something called pita chips. They were super oily and very tasty. I think they'd make great trail food. Lots of calories. Very durable to withstand packing. Eat with instant hummus or whatever. Make sure you don't get any kind of low-fat or low-calorie version of this.

ooh, Costco sells a couple types - some low fat, others high fat. All good ;-)