Well, it arrived today and I was able to do some basic User Acceptance Testing. It's pretty nifty. It has no problem powering a 25watt bulb, although it does get warm enough that I would probably use a heat-sink in a real installation. Since it's variable, it's real easy to set up a dimmer circuit that allows you to vary the voltage with a rheostat. For fixed voltage you just need two resistors.

Now I have to figure out how to mount it and where to put the dimmer switch.