Do you browse the Web on your phone, iPod touch or other portable wireless device? Congratulations, you're one of the 450 million mobile Internet users, according to IDC. The analyst firm today predicted that number would reach 1 billion by 2013.

I'll do some quick math. Apple has shipped more than 30 million iPhones, so there's a possible 6 percent or so of mobile Internet users -- and that's not counting more than 20 million iPod touch users. Another nearly 30 million Crackberry -- ah, BlackBerry -- addicts accounts for another 6 percent of users.

"Internet-connected mobile devices are reshaping the way we go about our personal and professional lives," John Gantz, IDC's chief research officer, said in a statement. "With an explosion in applications for mobile devices underway, the next several years will witness another sea change in the way users interact with the Internet and further blur the lines between personal and professional."

That change may be accelerating, with smartphones pushing the gas pedal. In October, Gartner reported that smartphones accounted for 14 percent of overall mobile device sales, but would grow to 37 percent by 2012. Gartner forecasts 180 million smartphone sales in 2009, exceeding notebooks for the first time. From 2009, Gartner predicts that consumers would spend more on smartphones than notebooks.

No surprise, mobile Internet usage is more informational -- search, online news and sports, e-mail and instant messaging -- and where recreational, downloading music and videos.

Besides, the mobile Internet forecast, IDC also offered up a plethora of other information about Internet usage:

• The number of Internet users will increase from 1.6 billion this year to 2.2 billion -- or one third of the global population -- by 2013.
• China has more Internet users than any other country -- 359 million growing to 566 million in 2013.
• The number of U.S. Internet users will grow from 261 million in 2009 to 280 million in 2013.
• As measured by percentage of population with Internet access, the United States hugely leads China.
• India's Internet population will grow nearly two-fold over the next four years. IDC didn't give exact numbers of users.
• The number of devices -- mobile phones, PCs and video games -- accessing the Internet is more than 1.6 billion. The number will grow to more than 2.7 billion by 2013.
• The United States leads the world with the most Internet connected devices, but China ranks tops for mobile Internet-connected devices -- 85 million, or nearly 20 percent of the worldwide total.
• The number of Internet users making online purchases exceeds 624 million worldwide. Online purchases will double, from $8 trillion to $16 trillion, between 2009 and 2013.
• Global Internet advertising will reach $61 billion this year, growing to over $100 billion in 2013. The 2009 figure represents 10 percent of advertising spending across all media categories. IDC forecasts 15 percent by 2013.

'The next several years will witness another sea change in the way users interact with the Internet and further blur the lines between personal and professional," Gantz expressed in the statement. He's so right about that.

Because it's not just end of the year, but end of the decade, I have a question for Betanews readers: How do you expect to be accessing the Internet in just five years? PEW Internet forecasts that by 2020, the mobile phone -- and not the PC -- will be the primary way people access the Internet. I predict the transition will be much sooner. What do you think? Please respond in comments.