Businesses who have bought an enterprise version of Gmail, found within the Google Apps software package, will also receive the feature for no extra money.

Google believes the voice and video feature will capitalize on the low barrier-to- entry to Web conferencing created in recent years, thanks to the proliferation of Web-based applications and cameras that have been built into computers as a standard feature.

"It opens up opportunities that weren't there before," says Rajen Sheth, the senior product manager at Google Enterprise, which oversees Google Apps. "And just from a Web-browser, you can initiate this functionality."

A Gmail user who wants to use the service also must install a small plug-in (only a couple of megabytes in size) to his or her Web-browser. Gmail runs in Internet Explorer, Mozilla Firefox, Google Chrome and Safari.

By launching the video chat feature, Google dips its toes into a market occupied by technology vendors new and old, including IBM, which sells a video functionality around instant messaging in its Lotus Sametime software, and Skype, a free service that allows people to video conference and place phone calls over the Web.

In addition to Google's business customers, Gmail caters to a large consumer base of what's estimated to be tens of millions. According to Sheth, the decision to add the feature stemmed from user feedback in both markets.

"We've gotten strong feedback from consumers as well as businesses: text chat is only one way they want to communicate in real time with other people," Sheth says. "Voice and video is the next logical step, and they wanted it to connect to their Web mail."

The addition of video bolsters Google's headstart over Microsoft in providing a fully Web-based package of producitivity applications — one that extends just beyond e-mail, word-processing and spreadsheets.

Since Google Apps launched in February, 2007, it has added a wiki technology (known at Google Sites) that allows people to build both internal and externally facing websites with no programming experience, a presentation application (think: PowerPoint), and the ability to upload and share video (think: YouTube for businesses).

Though Microsoft announced nearly two weeks ago that it was creating a Web-based Google Apps competitor, dubbed Office 14, it will not ready until late 2009.