ok guys I am new at this, coud somebody please tell me something: can the 770 use a ipod shuffle as memory? it is self powered you will need only the adapter or not?

Not "easily" no.

Although the USB interface on the N770 is "USB-To-Go", it does not actually seem to provide the 8mA@5VDC required to get a connected hub to accept the N770 as a USB Host-mode device.

If you search the forums you'll find a number of different cable+hub designs to work around this, but all of them are geared towards providing phantom power on the upstream side of the hub. You won't be able to connect a USB storage device "solo" the way you're asking about.