Wireless networking providers pushed sales of PDAs to a record high, up 2.7 percent from last year to 3.7 million units shipped in the second quarter.But hardware makers weren\u2019t as happy, as they watched worldwide PDA revenue fall 4.1 percent to US$1.38 billion, according to a report released Monday by Gartner.The problem was that, compared to the second quarter of 2005, the average selling price of a PDA fell 6 percent to $373, a victim of aging product lines and generous subsidies offered by wireless providers.Market leaders weren\u2019t able to react fast enough to the advent of integrated WANs, and the top three PDA vendors lost heavy market share to smaller vendors.Research in Motion (RIM), Palm and Hewlett-Packard (HP) are still the top three sellers of PDAs, but they all lost share to Mio Technology, Motorola and Danger.RIM saw its market share fall just 1.1 percent, but some competitors had steep declines, such as Palm\u2019s drop of 26.7 percent, HP\u2019s drop of 15.1 percent and Nokia\u2019s drop of 40.5 percent. In contrast, Mio Technology enjoyed a 65.4 percent rise in market share.More and more PDA models have keyboards, forcing vendors to innovate elsewhere. Mio was successful because it focused on one of its strengths, GPS satellite navigation, said Todd Kort, principal research analyst for Gartner.Still, Mio\u2019s ascent pushed it only as far as fourth place with 8.2 percent overall market share. RIM remained the leader with 22.5 percent market share, compared to Palm with 12.7 percent and HP with 10.4 percent.The other winner in this fast-changing market was Microsoft, whose Windows Mobile OS accounted for 54.2 percent of PDA platforms sold in the second quarter, compared to 22.5 percent with the RIM OS and 13.4 percent with the Palm OS.The Gartner study defines a PDA as a handheld computer used primarily for storing data, so these numbers do not include smart phones such as Palm\u2019s Treo 700w or RIM\u2019s Blackberry 71xx, but they do include cellular PDAs such as HP\u2019s iPaq 69xx and Nokia\u2019s E61. By Ben Ames, IDG News Service (Boston Bureau)Related Link:\n\nThe ABCs of WirelessCheck out our CIO News Alerts and Tech Informer pages for more updated news coverage.