When I saw the R-Pi, I knew what I wanted to do with it, I want to build one into a small case with a screen and battery and have it run classic emulators. So far I have settled on these main parts:
3.5" Screen (NEW 3.5" TFT LCD Color Screen Car Rearview Monitor DVD VCR | eBay)
Battery (YSD-998 5V/9V/12V USB Super Capacity Rechargeable Li-ion Battery (Black) - Batteries & Chargers - AirAccent.com)
I'm thinking of doing the controls by Hacking apart something like this (Speedlink Strike PC Gamepad - Red: Amazon.co.uk: PC & Video Games) I'll solder new buttons over the contacts on its PCB. fairly straight forward.
Ill probably also include a USB hub with a large (64GB or 32GB) pen drive, a wireless adaptor and this (3.5" inch LCD Touch Screen panel for 3.5 TFT LCD Module for LQ035NC111 | eBay eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices) touch screen and control board.
I'm including the pen drive to allow it to store a few movies and songs as well as games and emulators.
So far the only custom soldering I will need to do is for the controller, (simple enough) Making a little splitter board for audio so the feed can go to speakers or to headphones, a power splitter board because the battery provides the 12v I need for the screen but that is also the charging port so I will need to be able to direct the power to an external socket and a simple board to plug the wireless adaptor into, so I can turn it off easily.
For the Audio switching board, I'm thinking of making use of a socket that has switching contacts, which makes it easy to direct the signal.
for the power, the only thing I could come up with was a DPDT switch, to chose where to connect the +12v and 0v. the disadvantage of this is that I wont be able to charge and play, If anyone can think of a better circuit, please share!
For the Wireless switch, I am planning to simply solder a usb plug on one end of a board and a socket on the other, and wire a switch on the +5v rail. That should work as far as I can tell.