The Bifferboard is a very compact mini-computer with ethernet and USB. It is capable of running Linux and quite a lot of software. It's perfect whenever you need a power efficient cheap mini-controller for just about anything.
I have written a few guides relating to the Bifferboard and OpenWRT here. I wrote them for the purpose of remembering how to do things the next time I need to do them. Because if I don't write it down I will forget it.
Hopefully they might be useful to others as-well.