Just recently I got a PiFace Digital from Farnell. PiFace Digital is an interesting Raspberry Pi add-on board.
It features 8 digital inputs, and 8 open collector outputs, as well as 2 relays (NOTE: though the relays are rated at 250v at 10Amps, the PiFace board will support up to 20V, the relays are designed to only run at 5V). According to the official description, allows you to sense and control the real world. To be honest, this pretty much sums up the documentation for the product, or rather – lack of it. For now, I suppose, as it’s a rather fresh project. (...)
Read more at my blog: http://www.bartbania.com/index.php/piface-digital/