So far I have looked at the Raspberry Pi NOOBS Linux distributions: Raspbian, Arch and Pidora; the XBMC focused Raspbmc and OpenELEC; and the non-Linux RISC OS. Then in the most recent post I discussed the Pi Camera and USB WiFi adapters. Speaking of the camera, there was a very interesting new post on the Raspberry Pi web site about a python interface and a web page for accessing the Pi camera.
Now I have a couple more add-on hardware bits to explore, the PiHub 4-port USB hub designed especially for the Raspberry Pi and a Bluetooth USB adapter.