Visiting the Bike Barn, they had this NiteRider MiNewt Mini-USB rechargable headlight in stock. It is rated at 110 lumens; I almost believe it is more than that.
It will charge both from an AC adapter and a USB connection to a computer; USB charging is, of course, much slower.
My only reservation about the light is that it attaches to the handlebars using one of three different sizes of rubber rings. The small crossbar at the top of the handlebars of Bluetiful seems a tad small, even for the smallest ring, so the light does not seem to be very solidly mounted. I looped the power cord underneath the rubber ring, and it seems to be a bit better. There were no problems with the light falling out of adjustment on the two test rides, we'll just have to see how it works out on the commute.