Now, take a look at this, it's the new GAME BOY MICRO. There are two versions, one is purple, and the other is the Famicon "retro" version, celebrating 20 years of Super Mario Bros (wow twenty years already) for the Famicon/NES. It looks very good, but I'm not sure how confortable it would be to play with one of these things.

Translating the text on this forum: it states that it fits perfectly in the hand, even though it's so small you can keep it in your pocket. It's easy to hold the a, b, L and R buttons (notice how it's a lower "a" and "b", like on the revolution controller). You can remove the front and change it if you want. It also states that the sound could be a little bit louder, but the screen resolution is even better than the GBA and DS ones. It only works with GBA game packs, so you can forget about the old classic Game Boy and Game Boy Color ones...