The iPhone has been in people's hands only a short time, yet a recent study shows that Apple's combination media player and cell phone is already having a significant impact on watching video through a mobile device.

Market researcher Interpret LLC surveyed iPhone users and non-users less than 10 days after the June 29 release of the device and found 63% of buyers had already watched video on the iPhone. That number is more than twice the percentage of cell phone subscribers who have watched video on their handsets.

As to what iPhone users are watching, slightly more than half were checking out YouTube clips, while 46% were watching music videos. About a third were watching news videos or movie trailers.

While few non-iPhone users were interested in watching full-length TV shows or movies, a majority of iPhone owners were, Interpret said in the study released this week. Fully 57% were interested in movies, and nearly two-thirds in TV shows.

Having an iPhone certainly sparked an interest in video, the survey found. Only about a quarter of non-users were interested in video on a mobile device. But after seeing video on an iPhone, 73% said they were interested in watching on the Apple device. Fully 42% of non-users were "extremely" or "very interested," which means they were likely to watch video on an iPhone if they had one, Interpret found.

The study shows that there's a "huge untapped opportunity for mobile video," Interpret spokesman Jason Kramer said. "If the technology is there and the user experience is right, then consumers will watch video. Apple is proving that the market is there."

Apple stores, which have iPhones on display for people to try, could help in raising sales. Half of non-users who already had some interest in buying an iPhone, said they were more likely to buy one after watching video on the device. Depending on the size of storage, iPhones cost either $499 or $599, and require a two-year service plan from AT&T.

As to how iPhone owners and non-owners would prefer to pay for content, 60% of users and nearly three fourths of non-users said they wanted ad-supported video. Fully 73% of iPhone owners expected to get paid content from Apple's online store iTunes, compared to 43% of non-users. Fully 46% of non-owners expected paid content to come cable and satellite TV providers.