I was researching how to build a survival kit a while back, and just now stumbled on this pretty good article on how to make a mini-kit out of an Altoids tin - small, inexpensive, and practical. Enjoy.
DIY: Make an Altoids tin survival kit - DIY - Lifehacker
Here's another good one on how to build a "maker's tin" for you handy types out there:
Now I have to come up with an airsoft version!