I think a hammock is very convenient for camping / emergency use. I keep one in my BOB. It's lighter and smaller than a tent, and much MUCH more comfy. This is the one I use:
http://www.kmart.com/shc/s/p_10151_10104_1010000001265488P?vName=Fitness+%26+Sports&keyword=hammock

But now, I like the one aloha posted. I might have to get one. But here in South Louisiana, if you can carry along something that keeps the mosquitoes out, it's worth it.