With Windows Mobile 6, users will be able to view e-mails in their original HTML format and follow Web links from their phones. Windows Mobile 6 also will offer instant messaging and more robust editing capabilities for documents created in Office applications, such as Word and Excel.

Formerly codenamed Crossbow, Windows Mobile 6 boasts better search capabilities than predecessors, and stronger security features.

Feature Rich

Smartphones using the OS will be able to encrypt data stored internally on the device and also on a removable memory card. When used in enterprise settings, I.T. departments will be able to tweak security policies to require that users change their passwords regularly and use both numbers and letters, for example.

An additional change that has been put in place but will not come into play until later is support for Voice over Internet Protocol. Microsoft is not including software for VoIP calls, but has designed the system to allow carriers and device makers to include that capability if they wish to do so.

The integration of VoIP with Windows Mobile could be an indication of the evolution of mobile phones, noted Yankee Group analyst Jennifer Simpson.

"There's an interesting and ongoing development when it comes to VoIP and cell phones," she said. "There aren't a lot of dual-mode phones out right now, but there are some small niche products out, and major players like Microsoft are making room for partnerships in the future."

Market Basket

Microsoft's refresh of its mobile operating system is not surprising, given the rate at which phone users have begun to access data through mobile networks. According to a recent report from Gartner, the worldwide PDA market hit record shipment numbers in 2006, with a full 60 percent of all PDAs shipped last year offering some form of wireless connectivity, up from 47 percent in 2005.

Gartner noted in its report that Windows Mobile devices tend to be more enterprise-oriented than devices that are based on other platforms, with the exception of the BlackBerry.

But even in the more consumer-oriented fourth quarter, with holiday gift-giving the motivation for many purchases, Windows Mobile had its highest sales ever, with mobile OS shipments exceeding 3.5 million, an increase of 1.3 million over 2005. That strong quarter helped Microsoft gain a considerable foothold in the market, giving it about 56 percent market share for the entire year, according to Gartner's data.

Microsoft has expressed confidence that it can inch ever closer to making its mobile OS as ubiquitous on mobile phones as Windows is on the desktop. The software maker noted that it expects sales of mobile phones running on Windows Mobile to double this fiscal year and double again in the next year.