from the first link:
Here’s something for all those guys (and girls) who want to re-create the feeling of playing their favorite retro video games. The Mousou Controller is a key chain that looks like a mini console - and sounds like one too! Pressing the buttons is just like playing the real thing. Even the key combinations work in just the way you remember them. What’s more, you can choose your Street Fighter console depending on the characters you want to play.
This product is expected in stock on Saturday 20 March, 2010.
-Choose your Street Fighter II version: Ken, E Honda, Guile (blue); Ryu, Blanka, Sagat (red); Dhalsim, Balrog, Chun-Li (black)
-Size: 35 x 53 x 17mm (1.4 x 2.1 x 0.7")
Although it would make a sucky keychain, unless the sounds don’t go off in your pocket, unless it has an on/off switch that isn’t easily accidentally activated.