24 January 2002 From eMarketer:

In a recently released report, eTForecasts estimates that the number of PDA-phones in use worldwide will rise from 900,000 units in 2001 to roughly 49 million in 2007. eTForecasts defines a "PDA-phone" as a web cellphone with personal digital assistant (PDA) functionality or vice versa.

In the US, the number of PDA-phone units will increase from 46,000 in 2001 to over 14 million in 2007. Overall PDA unit sales in the US will grow to over 80 million by 2007 -- 17.7% of which will come from PDA-phone unit sales.

For comparison to the eTForecast numbers, eMarketer's North American Wireless Report presents information from Jupiter Media Metrix. Jupiter estimates that by 2005, 74.9 million people will be using voice-centric handheld devices and 7.3 million will be using data-centric devices to access the internet.