The new offerings should begin to bring desktop phones into line with their mobile counterparts when it comes to features such as simplified dialing and text input, said Zeus Kerravala, an analyst at Yankee Group Research Inc. in Boston. He added that until now, desktop models "haven't changed much in the last 30 years."

Avaya Inc. and Mitel Networks Corp. separately announced phones that are due to ship in July. In addition, an official at Siemens Communications Inc. said the company will formally announce a new line of IP-based and traditional circuit-switched phones in the fall, with a user interface that borrows from devices such as PDAs and the Apple iPod.

"The focus is on an easy user interface, something we borrowed from consumer electronics," said Joan Vandermate, vice president of product line management at Siemens Communications. The Siemens AG subsidiary will unveil up to six phone bodies that look "radically different" from today's desktop devices, Vandermate said. She added that the new models will include a USB port for connecting equipment such as wireless Ethernet adapters for linking the phones to Wi-Fi networks.

Avaya rolled out two phone models and said it plans to add another two to four by early 2007. The phones will have faceplates whose color can be changed, plus high-fidelity sound and a USB port for external connections.

LifeNet , a nonprofit human organ donation agency, is testing eight of the new Avaya phones at its help desk, which supports nearly 500 end users. Russell Stewart, information systems technical support manager at LifeNet, said he and the help desk workers have noticed a marked improvement in sound quality and ease of use.