An interesting open-source piece of hardware is Armadeus.
It combines a Xilinx FPGA (Spartan 6A) with with an ARM SoC (Freescale i.MX51), and that thing can run Linux with custom peripherals implemented on the Spartan!
(BTW, the iMX51 SoC has an FPU as well an is clocked at 800 MHz.)
