The number of worldwide Internet users surpassed 400 million in 2000 and will increase to more than a billion by 2005, according to a report by research firm eTForecasts. Growth will be fueled by surging numbers of wireless users who access the Internet via cell phones and personal digital assistants, and by 2005 they will constitute a majority of Internet users, according to the report.

An estimated 414 million people worldwide used the Internet by the end of 2000, with wireless users accounting for 40 million, or about 9.6% of the total. By 2002, the report says, the total will increase to 673 million people, and 225 million of them--about a third of all users--will have wireless access. By 2005, there should be a total of 1.2 billion people on the Internet, with 730 million wireless users accounting for 62.1% of the total.

Egil Juliussen, president of eTForecasts and author of the report, says the growth will come largely from Asia and Latin America, and that in developing countries wireless devices will be the primary or only Internet access device.

The United States had 135 million Internet users in 2000, but only about 2 million, or 1.3%, were wireless users. In 2002, the number of users will increase to 169 million, and wireless use will jump to 18 million people, or 10.4% of the total. By 2005, 214 million Americans will be on the Internet, and wireless usage will swell to 39%, or 83 million users. Juliussen says the comparatively tame U.S. growth rates vs. worldwide rates has mostly related to the high level of connectivity the country has already reached. "You can't grow any faster--there's not enough people," he says.

Juliussen says the wireless Internet has been hobbled in the United States and Western Europe by technology flaws, but once always-on service and useful content arrive, the number of users will surge. He says that in Japan, subway train schedules have proven to be "an absolute killer app" for wireless devices, and traffic information for commuters could be just as popular in the United States. "All the negative commentary about the wireless Web is deserved," he says, "but it's going to be doing well once we get our expectations scaled down."