I guess a lot of what I do falls into this category, but here are a couple small projects that I'll put out for your perusal. One can't take life too seriously.
I made this cannon out of some spare materials that I had laying around. The barrel and wheels were cut out of some 1 1/2" steel rod that was left over from the "mother of all home generators" project that I did a while back.
That's a story I haven't written up. I probably shouldn't be doing generator projects anyway, I discovered another time that if you're using a 240V generator, and the ground wire in the cable and house wiring isn't fully intact (even if it measures OK with an ohmmeter), you can end up with 0V going through some places expecting 120V in your home, and 240V going through other places expecting 120V. It can get ugly. The lights in some rooms are VERY bright for a while though.
But, back to the cannon. I made the sides from some left-over Delrin, which is a joy to machine. It's about 12" long, and weighs about 9 pounds. I bored it out to be 5/8", or 625 caliber. The pins holding on the wheels are just roll-pins. With a fuse sticking out the top, and a big ball bearing and some black powder in the chamber, it's a hoot to fire.
I had a little problem finding a beer-holder for my trout fishing boat. Most are designed to be mounted on vertical surfaces, but there aren't any of those near where I set my beer/coffee/pop (depending on the time of day). So I dug out some scrap aluminum plate and made this:
Speaking of boat projects, as a Christmas present, my nice wife gave me a remote control kit for my Minn-Kota trolling motor. Previously I've been trolling around the lake with the foot-control on my lap since it is sort of hard to run with your foot. Then I realized that the little remote control would quickly be in the lake, especially if I made too much use of my beer-holder, so I decided to mount it on the dash of the boat. The complication was that it was all rounded on the back, so it was tough to match that shape. It did have four screws that held it together, so I decided to just make a little plate with cap-screw heads sticking out that would touch against the screw-heads on the remote. Since they were a little pocketed, it also positioned the remote. Works well!