plah831 said:ooh, cool! I've thought about getting those, too, so I can watch my night feeders in action. I'm too poor for the whole fixture, though, and can't sacrifice a bulb in my overhead light as I have live plants. I'd probably go with the stick-on 1W ones, if anything.
eBay has LED moonlights cheap, less than $30 shipped (for the 10-LED). How big is your tank? There's a 5-LED version for small tanks, 10-LED for ~10-20gallons, and 20-LED for 20+ gallon tanks!
You can also daisy chain them if you have a larger tank, and they also have a controller/timer to control each set of lights (I think), but those are pretty $$$. Just check eBay for "moonlight led" and you should get some hits.
There's also a few submersible neon bulbs, but I wouldn't trust anything actually submersed into my tank.