Telecommuters and remote workers are closing in. Recent improvements to enterprise voice-over-IP (VoIP) are promising to make the concept of location irrelevant.

VoIP’s march through the enterprise telephony landscape threatens to leave several casualties in its wake, and not just private branch exchanges (PBX).

Adventurous businesses making the transition to IP telephony are beginning to realize that the technology’s real value lies not in cheap phone calls, as most think, but in the really cool things you can do with it.

For example, the ability to integrate your VoIP with Microsoft Outlook, or even your mobile phone. And the ability to replicate your instant messaging experience in your voice calls.

The rise of IP telephony, analysts say, will lead to the demise of the importance of location, among other things.

There is no question that IP phones will take the place of traditional PBX phones in the enterprise market. According to research firm In-Stat/MDR, the number of IP lines in the U.S. will rise from 5.5 million in 2003 to 7.7 million in 2004, and will reach 16 million in 2008.

VoIP phone calls are cheaper, but that’s not the only factor driving companies to switch.

“I think businesses need to realize that IP telephony is not about cost-saving alone,” says Jeff Snyder, analyst with Gartner. “It’s capable of making some real improvements to the workplace.”

Such improvements include the integration of corporate directories into the telephony system, says Mr. Snyder, which allows users to dial other people in the organization by simply clicking on their names.

He also sees the increased use of “presence awareness,” where the program finds out whether or not a user is available and reachable by phone, much like IM does. Since users will be identified by IP address instead of phone number, they will be reachable whenever they are connected to the Internet.

“What all this means is that telecommuting and working from a remote location will become a reality,” says Mr. Snyder. “Some call it the ‘death of distance.’”

Norm Bogen, director of networking at In-Stat/MDR, says he is most excited about the integration of VoIP and cellular technologies to produce a dual-band phone that will operate as a wireless phone outside the office building, and connect through the wireless local area network (WLAN) while inside.

“It will allow seamless roaming,” he says. “Initially, the wireless companies may be reluctant to offer this service, as they will not want to lose the minutes while the user is inside the building, but this is a big trend you’re definitely going to see.”

A recent collaboration between Avaya, Motorola, and Proxim may make this a reality. Their solution includes a dual network phone from Motorola that functions as an Avaya phone while in the office. Voice communications are supported on the WLAN within an office building and on the mobile network while workers are outside.

Bryan Martin, CEO of broadband provider Packet8, says that this might be the ideal time for companies to embrace the concept of a virtual office.

“Imagine having one man in charge of several departments,” he says. “Consumers call different extensions, but all their calls are answered by one person, who can tell which department has been called by the ring tone.”

Mr. Martin also believes that branch offices in various cities can be connected by simple extensions, allowing for seamless coordination.

A recent survey by Changewave Research showed growing confidence on the part of the corporate sector to embrace Internet telephony. Among the respondents, 29 percent said their company will increase spending on VoIP in the next six months, while 84 percent of VoIP users said they were either somewhat or very satisfied by the primary equipment provider.

Brian Riggs, analyst with Current Analysis, says the most important trend in the Internet telephony space will be the integration of voice with enterprise applications.

“Imagine being able to dial a number by clicking on a name on Outlook,” he says. “We had people talking about CTI, or Computer Telephony Integration previously, but it never really took off. Now might be the time.”