Nokia 770 USB Power Hack
 

Won't a self-powered USB hub do the job? Maybe not as portable, but if I'm using a USB keyboard, I won't be lugging it around the country . . .

Hmm, maybe something like this:

CYBERPOWER (CP-H420MP) BATTERY POWERED 4 PORT HUB

http://shop.store.yahoo.com/pcsound/cph420mp.html

would work as well. It's more expensive though...

Yes, a self-powered USB hub will also do nicely.

But will the Nokia 770 support a hub?

=>
it say usb host work but it don't supply power for your device.
There is no problem with an alimented hub i think, just use the flasher command to use usb host

$2-3 to build? Yeah, right. You left out the $$$$ for the EE degree people need to understand that schematic!

Back to talking about battery-powered hubs...

flash drive support?
 

Can this be used to connect a usb flash drive? :cool:

Nokia Charger
 

How about using the nokia charger (supplies 5.7 V) as the power source. It might be a tempting alternative. Anyway, whenevery you are near a usb keyboard, power can't be that far away. Although for using it as a card reader, 9v battery is much saner choice.

Also, a splitter could be made so that you can connect the charger to 770 at the same time as it's powering the usb.

In the schematic above an important point has been left out:
GND must be connected to the 770 as well...
As I said in another post, in the event that the usb port on the 770 doesn't provide +5v (wich i find hard to believe...), and if the battery inside the 770 has 5v, or close to that, it "might" be possible to connect a plug to the 770's power input, and leech the 5v from the battery...
anyway...
the best thing is to use a mini usb hub with an external power supply...
(these are very cheap... I bought 4 port usb2.0 mini-hub for 7eur...)

batteries are't a good idea.. because if they fail while you're recordind into a usb pen drive, you will most likelly loose that data.. as well as everything else on the pen...