So, you've got your shelter built next to a decent water source, a good little fire going with enough wood for the night, you've eaten and made yourself as comfortable as possible. Is there anything you have in your psk etc. that can help you pass the time and lift your spirits?

I always thought a simple little harmonica would come in handy. Some folks recommend a set of playing cards or something to read. What, if anything, do any of you keep in your survival gear for entertainment?