Originally Posted by
varuscelli
I don't know if this would work for you in the configuration you are describing (or close to it), but I've always liked the looks of the Nitto Lamp Holder. I don't own one...but I'd like to.
They're fairly expensive, though...and do take up some space on the main handlebar.
And we have the winner for finding the device in exactly the same way as I would design it.