The Raspberry Pi is one tiny computer that's actually functional enough for modern use. It doesn't get any more barebones than a little circuit board with a 700MHz ARM 11 processor, a USB port, an HDMI port and an install of Ubuntu Linux.
Designed by game developer David Braben and his friends, the Raspberry Pi's basic structure was created to encourage schoolchildren to hack and mod it to unlock its true potential. On the stock Raspberry Pi, all one needs to do is plug in a display through the HDMI port and a keyboard through the USB and it's good to go — getting online requires another adapter.
While pictures show only a processor, USB and HDMI port, Raspberry Pi's website actually reveals its other secret powers: 128MB of SDRAM, OpenGL ES 2.0, 1080p HD decoding, composite output, SD card slot and other flavors of such software such as Iceweasel and Python. A 12-megapixel camera sensor can also be connected (as seen in pic above).
Braben is hoping to manufacture these little "computer" boards for about $25 a pop and let the world's future Bill Gates and Steve Jobs run wild with it. So, run little monsters, run, we want those embedded cellphones in our ears and HUD displays in our eyes before we're dust.