One of my favorite sites "Hack a Day" was running a contest to slap their logo on something and possibly win a Trinket by AdaFruit. Since I didn't have an ion beam to win the small category and didn't have access to any giant building light arrays I thought of a creative way to spray paint something.
A while back I had picked up two surplus ammo boxes which are perfect size for a traditional geocache. I took their logo image and made an outline of it so I could print just what I needed to cut it. After printing the outline I sliced it up and left a small strip to keep the eyes in the appropriate places. A few sprays and the logo was on. Here is a link to the article:
Now I need to find a place to stash it. I'll probably need a nice label on the top and side and maybe a QR code to scan when it is found, or a log book for the traditional people. It would be neat to have a few electronic projects to put inside. I'm open to ideas.