super simple luxeon headlamp/li-on combo (afordable)
take a Streamlight Argo HP, 2x CR123 headlamp (aprox. $25) then add one 17670 or 168s li-ion cell. that's it...
guilt free lumens and eliminate reverse charge danger by going to a single li-ion cell.
this has got to be the smallest headlamp with this much mah capacity. Argo HP is not as durable as Stenlight, but stands on it's own merits with li-ion cell.
note: to avoid overtighen cap problem with Argo HP. remember to unscrew 1/16 turn after seating cap. since both batt caps look indentical, to avoid killing you hands trying to remove wrong end. mark the cap that actually comes off.