It just so happens that I have the Proporta USB Portable Battery / Charger and it will work wonderfully with the N770. It has the Old Style NOKIA Head as well as the new slimmer style for All newer Model NOKIA Phones (and the N770) It also has a Reg USB to Mini USB 8 inch cable as well. The Portable Battery Pack is quite handy as you cann charge the N770 from the 3400mah battery or use the enclosed retractable cable as a regular USB charging cable. You get two in one. Also, if you have a few extra dollars, they have the Battery kit coupled with their new Gadget Bag (CLICK HERE) which is perfect for the N770 and all your gear. I have that and love it.