This is the one I want to use. Claims to be Linux compatible. Is that enough ??
I bought this one:
It works fine on a pc with windows 7.
It works on a PS3.
I can't say whether it works on the Raspberry Pi, as mine hasn't arrived yet.
BUT: I have an old pc loaded with Debian Squeeze + LXDE (following Liam's tutorial, missing out the VirtualBox bits) and the keyboard works out of the box with it, no problems.
As a keyboard it's fine, although IMHO it's too small to use as a main keyboard. The touchpad is a bit fussy, but I've got clumsy fingers!
They now do one with a built in IR controller instead of the laser, I would have bought that one if I'd known about it:
Also a bluetooth version and a wireless one without the laser or IR.