The plan is called BroadbandAccess Connect, and costs $60/month, which I'm guessing is a $15 premium over what you're paying for unlimited data access ($45/month last I checked.)

Bluetooth tethering for EV-DO is explicitly disabled on every Bluetooth non-smartphone Verizon sells, at least, not without BroadbandAccess or firmware modification. Most phone firmware does not differentiate between mobile originated data and tether originated data, but Verizon's does.

When I say tethering, I'm referring to doing what Cingular (well, kind of) and T-Mobile support already --- using your phone's data plan through your 770, and saving $45/month.