This is so easy that it's not even a project, but it was an essential part of my kegerator so hopefully someone else will like the idea. My kegerator is in the basement and the basement used to be pretty much unfinished so a big plastic tray on the ground was fine as a drip tray. Now the basement is totally finished so I needed something that was a little more presentable and something you wouldn't trip on. I saw the trays you can buy at the LHBS, but I'd rather put that money toward ingredients or other equipment. I went to the hardware store with no plan and left with a drip tray system for about $8.
I have two taps so I picked up two metal soap dishes.
Then I got a couple strong magnets (AA battery for scale) and stuck them to the back of the soap dish. The dish is magnetic of course.