Obama campaign manager David Plouffe announced this morning on a conference call with reporters that the campaign will start advertising in three more states beginning later today. They will go back on the air with TV ads in Georgia and North Dakota, and will begin airing a TV ad in Arizona for the first time.

"Essentially we're playing alone," Plouffe said, noting that McCain isn't on the air in the three states. "For a while we were playing alone in North Carolina, Indiana and Virginia, and I think we benefited from that."

UPDATE: Here are the ads that will air in the three states...

"Rearview Mirror," airing in Georgia and North Dakota:

"Something," airing in Arizona: