The model B has 256MB RAM, 2 USB ports, and Ethernet port, HDMI out, composite video out, and 3.5mm audio out and an ARM11 central processing unit. The GPIO header allows connection of other circuitry that can be controlled via software running on the Pi.
I finally got round to designing and printing a case for my Raspberry Pi.
I designed it using Art of Illusion. This is a simple 3D modeling and rendering package that is quite basic, but simple to learn. The bottom part has a slot for the SD card and cutouts for the power, HDMI, Ethernet, USB, audio and composite connectors. The top has three little slots for ventiation and snaps onto the bottom, no need for screws.
It needs a little tweeking. One of the mounting points for the PCB needs moving a little, the lip on the top part is little too big and the slot for the power doesn't line up. Once i fix these issues i'll upload the design files here and on Thingiverse.
Check out the raspberry pi camera and the pi cobbler.Pi Camera Pi Cobbler