My Alfine dynohub is 680 grams, which is about 540 more than the Ultegra it replaced. That's 1.2 pounds extra just for the hub. I have to agree, drag's negligible in actual use. I'm still not very happy with the light output, but maybe I'll try a Schmidt eDelux if I get a tax refund that'll cover it... they appear to have more throw.

In point of fact, DiNotte's entire high-end headlight, with 4-cell Li-Ion battery pack, weighs less than my dynohub alone. Way less. For about 5x the light output. And I think it's cheaper than my hub/headlight combo, too! *hastily cuts up credit card*