Text-messaging and taking a photo were easily the most popular non-voice activities, with 58% of mobile users doing both at least once. Playing a game (27%), sending e-mail (19%) and accessing the Web for news, weather and other information (19%), rounded out the top five.

But on a typical day, only 31% used mobile devices for text messaging, and 15% to take a picture.

The study released today marks the first time the Pew organization has examined mobile data access. It also showed for the first time that the cell phone would be the hardest communications technology for people to give up. More than half (51%) said it would be very hard to give up their cell phone, compared to only 38% in 2002.

"Even in 2006, the landline phone was still the most difficult device for people to do without," said John Horrigan, associate director of research for the Pew Internet Project. Underscoring the premium placed on mobility, the cellphone now also trumps the Internet, TV, e-mail and the BlackBerry or a wireless e-mail device.

Not surprisingly, the Pew study found that young people and Hispanics are among the most active mobile data users. On a typical day, more than half of English-speaking Hispanics do something on their cellphones other than talking. The emergence of Hispanics and African-Americans as early mobile adopters stands in contrast to the early days of the desktop Internet, noted Horrigan.

"When the Internet was first entering mass culture, users were mostly white men," he said. "But for this new type of access to data and information we're seeing a different adoption pattern than during the desktop dial up days."

Horrigan attributes the change to cell phones being relatively inexpensive and easy to use compared to PCs a decade ago.

Similarly, 60% of people under 30 use their cell phones to text-message on an average day. About the same percentage in that age group also send or receive e-mail daily. "Text-messaging by and large seems to complement e-mail use rather than substitute for it," Horrigan said. "If someone's an active texter, they're also likely to be an active e-mailer."

Ethnic minorities and young users also lead the way in connecting to the Internet on a laptop or device while away from home or work. Accessing the Web on the go was done by 65% of Hispanics, 54% of African-Americans and 70% of users under 30.

Even the 19% overall that access the Web via mobile device was higher than Horrigan expected, however. "I was a little bit surprised at how high those levels were for people generally since (wireless) networks for the most part still aren't that fast for accessing the Internet."

The Pew December 2007 study was based on a survey of 2,054 Americans 18 and over, including 500 respondents contacted on their cell phones.

In a separate study, comScore released findings on Tuesday showing that the number of computers who access the Internet through high-speed mobile connections had more than tripled to 2.1 million in 2007. While only 1% of the U.S. Internet population goes online via mobile broadband, the technology is poised for major growth in the next few years, according to Serge Matta, senior vice president of comScore.

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