One of my colleagues got some of these in at work.

http://www.ebuyer.com/customer/produ...uct_uid=106145

Its not 100% as per the picture, but 99%. The interesting things being
a) The size (very small)
b) It has an external power input which is the normal Nokia size/type.

We only had the older (ie. the one a size up from the 770's power connector) PSU at work, but this fitted and worked fine.

Lop the USB end off, solder on a mini-a and job done

(Or one of these http://www.vernier.com/accessories/a...ate=basic.html , strip the wires back midway along, change them and put some heatshrink over it. That way you've got a generic hub for use on other stuff too).

Get one of the "emergency" rechargeable external Nokia battery packs to plug into it and you've got a nice small, technically competant solution.

Just need to order one for myself to test the theory.....

I'm hoping something like that would work. I bought a tiny USB hub as well as an APC USB backup battery. When I hook up the APC battery to any of the USB ports it seems to power the hub (a red LED is lit on the hub). I just have not figured out how to program the 770 to accept USB attachments yet.