The Presidents of the United States of America (the band) have put together a music video comprised of footage shot exclusively with cell phones.
From the Presidents’ site:
The director of the video, Grant Marshall from Film Headquarters, said he was very excited when Presidents of the USA agreed to this idea. He came up with the idea after the company’s creative team lamented how budgets for Australian music videos were far lower than those for international clips. Producer Nick Wolff said “We joked that budgets were getting so small that the next thing we’d be doing is shooting on a mobile phone.” (emphasis mine)
And that is exactly what they did. (Link has various video format choices)