Though this simple and elegant game system fits in your credit card slot, you don't want to sit on it.
Some accidents are happy accidents. In this case, the accident happened to be dropping a surface mount resistor into a hole on a PCB. It fit perfectly, which gave Kevin Bateske the inspiration to incorporate this concept into a project.
The lucky recipient of this design method was the Arduboy, an Arduino-based game system with capacitive touch buttons and an OLED screen. The screen happened to be roughly the same thickness as the PCB, and so was the battery. Having these multiple components suspended in cutouts would surely be a striking visual concept.
A prototype using a Qdoba card.
Bateske prototyped the idea in a few different ways and ultimately designed a PCB. His order came in, and he found it almost perfect. The only unfortunate issue was that the spot for the AtMega was not milled out. A friend help cut a nice, clean opening, and if Bateske didn't tell you that it wasn't professionally done, you wouldn't even know it.
Hand-cut hole for the AtMega.
He has not released the files for the Arduboy yet; he says he would like to use crowdfunding to make the necessary changes to make this a releasable project. The reason for the additional cost is to get a license for Cadsoft Eagle, as well as cleaning up the code and improving the design.
On the list of improvements, he mentions that he should probably switch to resistive touch sensors. Capacitive sensors are interesting and can supply force measurements, but they aren't as reliable as resistive ones.