My son and I made pill bottle first aid kits last year in his Cub Scout troop. While I really liked the fact that his pack leaders were teaching the kids how to be prepared for small emergencies, I decided to take the original design and upgrade it a bit. This is my take on how you can design a very inexpensive mini first aid kit that will be invaluable for most situations, while at the same time taking up very little space in a backpack, purse, pocket, or car's glove compartment. I keep one with me at all times, one in my desk at the office, and have insisted that my wife carry one as well. My son has a modified version in his backpack, without the matches or lighter.
Now, the kit that the Scouts built was primarily geared towards first aid, but I felt that, with the right modifications, you could diversify it's uses without adding a lot of weight.
The best thing about this kit is that you can put it together for less than $4.00! I'll explain how in the steps.