Tinkerer and author John Graham-Cumming (he wrote the Geek Atlas) created an Arduino-based gaming system that fits in a can. [via]
On the left is the main controller (the power switch is visible) and on the right is the expansion controller with its cable. The left (red) controller also has a ‘fire’ button that isn’t visible and both have simple ‘paddle’ style controls.
Cansole: Arduino Based Video Game Console in a Can - [Link]