Level of difficulty (1 being easiest, 10 being hardest): 7

Dental floss is good for more than just oral hygiene. In the wilderness, it can be used for repelling, tying sticks together, or even suspending your things off the ground to keep them out of the reach of animals. It can also be used for small animal traps, as well as fishing line.

[via adventure.howstuffworks.com]