How about Gizmo with Grandcentral ?
Grandcentral dials the landline/cell you want to call and you. so you get a pc-call @ your gizmo (which are free) and on the other end is the person you wanted to call.
Read up the threads about Grandcentral here and decide if it is what you wanted.
I got free in/outgoing calls on my N800 with my own phone number that even fits my area code (u.s.).
johenkel