Too add to/contrast Brian's succinct and thorough post I'll mention what I do. I typically use a quart ziplock and find a 8.5x11" printed map folded in half and trimmed of all borders fits nicely. I print my maps off of CalTopo.com The quart bag fits nicely in my pocket and the whole map is visible (front and back of the quart bag). Additional maps are folded inside of the one that I want visible. I usually carry 2-3 high detail maps to cover my entire weekend trip and then one more lower fidelity map that covers the larger area. The stack gets folded in half, inserted in the bag then I slip my car key, drivers license, credit card, fishing license and some cash down the middle. It is my interact with and get back to society bag.