Money is a beautiful thing, and better yet -- it can be used for origami! With a dollar bill I'll show you how to make this unique guitar. It is a little hard to make once you get in depth with it, but it is a great present to give to your friends when you don't want to buy them something.
Step 1: Folds First
Take your dollar bill and fold it in half lengthwise, then unfold it and fold the long edges in to the center crease. Flip it over.
Step 2: Repetition, Repetition
Fold the bill in half width-wise, then unfold it and fold the bill to the crease in the middle. Return the bill to its normal position and fold it to the 1/4 crease. Unfold and fold the bottom edge up to the 1/8 crease. Flip the bill over.
Step 3: More repetition
Fold the top flap down to the bottom edge and unfold. Now fold the bottom edge up to the middle crease, being sure to let the paper behind swing out.
Step 4: The neck
Fold the top part over to the right or left and let the paper that binds it with the piece behind come out as a triangle. Flatten the triangle and fold the top half back in position with this new modification. Repeat this on the other half. Now fold the long edges of this stem to the center once, and then do it again (Twice).
Step 5: Refine
That leftover part behind the stem needs to go. Fold it back and sink it in the guitar. I sort of crimped it in.
Step 6: Back bending
Take the front flaps and pull them up over the stem/neck. Fold the body up in fourths, then unfold and flip over. Fold the bottom edge up to the nearest crease, then unfold and find a way to get it inside the body. I unfolded the body and stuck the edge in there, but there are certainly more ways to do it.