One of the things I love is any type of CNC device. I just heard about the Piccolo super small CNC based portable plotter.

It's essentially a kit that you need to source and to yourself, made from MDF, card stock, acrylic, an Arduino-alike controller board, some servos, and a few screws.

It's on my already impossibly long list of "I'm going to make one of those one day" things.