Bus from Hanoi to Phonsavan, Laos (or anywhere in Laos)

Does anyone have information on taking a bus from Hanoi to Phonsavan or anywhere else in Northern Laos?  I know about the Vinh to Laos route, but we want to leave from Hanoi.  We think Phonsavan would be a good start for our one month trip around Laos but are open to pretty much anything.

There are buses running from Vinh to Phonsavan. Takes 12 hours. There was a bus from Hanoi to Phonsavan. Check with travel agents as I am sure with the increased flow of tourists between Laos and Vietnam there is bound to be buses running. Since ASEAN set up it is really easy for them to travel across borders.