For our example, we've used a plug server. You can of course use whatever computer you like, but a plug computer is advantageous in so much as it consumes little power and is small and discreet.
Skip all this and get a FooPlug, preinstalled with GNU social and everything else in this list. Complete with a high-speed SD Card and USB backup flash drive, you can save yourself a lot of hassle and support our cool company at the same time.
You will need:
USB Memory Stick -- just use any memory stick you have to hand.
SD card -- Get the best balance of speed and size in an SD card that you can. We used a 4GB Class 6 card.
Once you have all of this, we should go ahead and install the operating system.