Dangerous Prototypes never ceases to amaze me with how they are the poster child of open source hardware. You can literally go back in the forum archives and watch their products evolve as members bounce ideas back and forth. Then, in the end, they post everything online with an open license, get a batch of 100 put together to sell some, and let people do with it as they will.
As part of this amazing outfit, they give away free PCBs. I've gotten a few before, and I got one again. This is their USB IR adapter, to allow you to give any computer infrared transmitting and receiving capability, which is valuable if you want to use your computer to receive commands from IR remotes (we have a computer set up as a DVR at home), or want it to be able to transmit IR commands to any other device which expects them.