Found this today on LifeHacker, it’s a do-it-yourself job that this fella cooked up to control the air conditioning unit over his home network. If you’re handy with electronics and computers, just wire in a logic board (or in this case a network addressable snmp aware relay board) connect it up and you’re hauling the mail. Well, after a little work.
Sure does look like it’d be a lot of fun to build, but not at the cost that board is going for. I’m sure one could find something similar at a cheaper price. Worth checking out though.