Wonder would it charge a Garmin 705 via USB?
Very interesting device. I can't understand why the manufacturers haven't come up with a way to charge AAs.
That's what the Ride and Charge does though the batteries have to be in the headlight.
Here's the B&M info:- Busch & Müller KG
You can link the R&C info from there (how's your German ?)
Peter White has info as well:-http://www.peterwhitecycles.com/PDFs/B&M%20Ride&Charge%20Inst.pdf
Expensive option since you have to get a dynamo, headlight and the R&C, but it is a good light.
I haven't fitted the R&C yet- I'm waiting to get my new bike because some faffing will be required.
If anyone wants to borrow my Copy Cat Solar device (the one linked to by Polar Bear), they're very welcome- let me know.
And, like several of you, making my own really isn't a good idea