I’ll come right out and say that this is NOT an LED for lighting your tank, but if you are like me, you’re constantly fiddling with things in dark places around your tank, the sump, a wiring closet, etc.  I have a pile of small LED flashlights for this purpose but that requires a hand to hold it and is not very maneuverable.  The Flexit is the latest in a series of positionable lighting systems but takes it a bit further with an entire mat of bright LEDs that can hold just about any position, including sandwiching itself around a board.  The Flexit uses 3 AA batteries and also has a hanging clip so you can put it on a nail or sharp edge.  The Flexit is available from many retailers, Striker has it for $29.99.