An experiment, if you will. Place two sets of headphones in opposite corners of an empty room and leave for 15 minutes. When you return, you’ll find them both in the middle of the room, tangled together into a knotted mess. For extra fun, try this experiment when you’re running late for an important meeting. You’ll find that they’ve doubled the knots and tied them extra tight! If you’ve got an old contact lens case, though, you may be able to avoid this problem.
A dead-ass simple Instructables How-To tells a tale of a heated exacto knife, a small slit in each contact lens compartment, and a simple wrap of the cords around the center section of the case. You’ll have to find earbuds that’ll fit inside the screw-on caps and be careful when cutting the slits — if you don’t want to heat up an exacto knife, you can use a different blade, although the Instructables’ author, mowdish, warns that you’ll have to cut slowly because, “The plastic is a little brittle and is prone to splitting if you apply too much pressure.”
Everything else looks pretty quick and simple, though. I have about a skillion old lens cases around here so maybe I’ll give this a whirl before my next trip.