RISC OS Pi
RISC OS Pi is supplied on a specially-branded 2GB SD card which has been created and tested by RISC OS Open specifically to avoid the hassle of creating your own bootable card for the Raspberry Pi.
Eben Upton, from the Raspberry Pi Foundation, has the following to say about RISC OS Pi: "Having spent a lot of time in my youth pining over Acorn Archimedes and RiscPC products, it's a great moment for me personally to see an evolved version of the original ARM operating system brought to the Raspberry Pi. From the Foundation's point of view, we welcome the arrival of an alternative desktop environment, offering a rich suite of applications, and with BBC BASIC only a few keystrokes away."
The RISC OS Pi SD card can be yours for just £10 plus VAT, P&P.