Theremin Mini Kit
ThinkGeek is offering a Theremin Mini Kit, a small entry-level battery-powered theremin that is “super easy to assemble (the electronics arrive already soldered together), but takes practice to master.” It’s a Japanese product and it comes with a magazine that is described as “gorgeous” and is full of pictures/articles. It also comes with mini sheet music.
Here’s a video of the assembled mini theremin in action: