Skype is testing an enterprise version of its VoIP service and is asking businesses with more than 1,000 employees if they're interested in getting in early.

"At this time, we are at the very beginning of testing an enterprise offering and Skype is inviting a limited number of businesses to be part of an early adopter program," a Skype statement said. "We look forward to hearing from business users at the early stages so we can make sure that we create a really great product that people love using.”

A spokesman said that interested parties should send an email to [email protected] with details about their company and how they plan to use Skype.

Skype has already attracted small and medium-sized businesses, Skype officials noted. In December, Skype announced enterprise-friendly features in Skype 3.0 designed to give IT managers more control.

The Skype services help businesses make "very cheap or free calls to millions of people all over the world," the statement said. "We want to work with businesses of all sizes to help develop Skype and make it even easier to use - especially if it helps companies save money and be more productive."

Skype's service is just one example of the ways that voice over IP is proliferating, said David Lemelin, an analyst at In-Stat. Businesses are turning to VoIP as well by installing dedicated IP voice switches or purchasing dedicated VoIP hosted services from large carriers, among other methods, he noted.