Round LED Wing Tip Lights
I bought a pair of them and they seem pretty nice. As per the plans, they are just glassed into the wing tip cut-out and aren't aim-able. I made up a couple brackets so I will be able to adjust where the light goes.
They're pretty low power, 0.9A @ 14v, so I am going to use them as taxi lighting. I held the wires on the battery terminals of a running vehicle and shone them down the street, they're defiantly adequate for taxiing.
I have one of the 50w Duckworks HID lights in a leading edge for landing. It is many times brighter.