A small (approx. 1 foot cubed) cobalt blue computer sold by Cobalt Micro. These machines run linux (although the user needent know that), and are popular with VARs.
VARs?
I've used 'em, they're decent. The small size means they're cheaper to colocate, the MIPS chip is decently fast, but mips-linux doesn't always have libraries available, so not everything will compile.