Here's a good fit for your emergency kit: Get double-duty from a few cans of tuna. Sure you get the food, but not so fast with the eating! You also get an oil lamp that'll burn for hours.
The tip comes from DIY site Atomic Shrimp, which notes:
Using a can of tuna in oil (the cheaper the better - as there's less fish and more oil that way), you can make an emergency lamp that will burn for several hours.
If care and hygiene is observed while making it, there's no reason why the tuna can't be eaten afterwards too!
Sounds like a winner to us.
Emergency Tuna Can Oil Lamp [Atomic Shrimp]