Someone correct me if I'm wrong, but I believe the Andrew Wynn "Nano" is a 3 stage AAA luxeon light- the only catch is that you have to run it on a Lithium Ion rechargable AAA cell.
Peronally, I'd love to see a single stage, regulated AAA luxeon light using a standard cell that underdrives the lux to around 5mm brightness levels. This brightness is all I need from a keychain light and a luxeon will gobble AAAs if driven harder. An Arc AAA with luxeon beam quality would be sweet!
