If you use stompboxes or a variety of other smaller electronic devices, you probably have a number of different wall wart and "lump-in-the-line" power supplies that go with them. The problem is that it can be hard to tell which supply goes with which box, and manufacturers rarely label their supplies. In most cases, plugging in the wrong supply won't do serious damage, but there certainly are cases where plugging in the incorrect supply sends a puff of smoke out of the box you want to use - not good!

The easy solution is to label each power supply indicating which box it powers as soon as you get it. This way it's easy to keep them straight and to prevent any damaged gear.