I had this toy on my wish list for ages and I finally got my hands on ! This is a DIY 35 mm Stereo Pinhole Camera made by Gakken, a pretty cool magazine in Japan where each issue comes with a different kit to assemble.
I'm quite impressed with quality of the kit, you don't need to understand Japanese and all you have to do is follow the pictures. I thought it was easy to put all the pieces together, everything fits well and as a result I got a really well made plastic camera with a cool design. The stereo viewer is the downside as the tapes provided were not good enough to keep the lens in place.
The camera has two modes: the stereo and the panoramic. I've already got a stereo camera so I took most of the shots with the pan mode, and I love it... I really recommend, specially if you want to try stereo photography. Most of the good stereo cameras are quite expensive and you might pay over £150.00 for a good one. I know there's been some plastic stereo cameras around (Loreo and Holga) for a reasonable price but I don't think you have the option to do both formats, besides the DIY fun and design are unique.
The picture below was the only one I took using the stereo format and later transformed into anaglyph file, in that way you can still see the 3D effect using a pair of red and cyan glasses.
My DIY chart with the exposure times that my Japanese friend kindly translated.