This is a simple way to use your earbuds from your ipod etc as a backup means playing music for a small group of people. I got the idea when I saw someone cupping ipod headphones in their hand to get a slight boost in volume. This is a simple "what if" project, if you have any suggestions on changes to the design to help increase the volume let me know, that's one the reasons I'm putting this up :-P
Step 1: Stuff you need
2 identical cardboard squares (mine were 5"x5")
Step 2: Cut triangle out
Draw/imagine a line going from one corner of the cardboard square to the opposite corner, follow line approx half way across the square (to the middle). Repeat with an adjacent corner to cut 1/4 of the square out. (Pictures make more sense :P)
Step 3: Fold and tape
Use the scissors to press into the cardboard and make a line from the 2 complete corners to the center of the square. This makes it easier to fold, once the lines are pressed into the cardboard, just fold the 2 flaps until they touch. Tape the flaps together, congrats you're almost there!