kc2ixe,
Miller modded Fenix's are L1Ps and L2Ps turned into two level flashlights by Eric Miller. I tihnk they become a twist for on light, with the switch toggling between high and low. I believe the high setting is a bit higher than the unmodded Fenix's output, though I'm not sure.

He has also put some Luxeon emitters into some other flashlights, like the ArcAAA and the Arc "clones" (ie ripoffs). I'm sure he has probably done some other stuff. A search over at CPF should reveal a lot.