Google is adding POP3 to its Internet e-mail service, Gmail, in the next few weeks, opening it up to the wider world.

With POP3 installed, the service, which is still officially in beta, becomes more public as PCs, handhelds and other devices will be able to download e-mail from Google's servers, rather than only view them online, as previously.

It marks the final stages before Gmail is made public - currently you have to be "invited" to try out the system. Launched in April, the service has already caused radical changes in the Internet e-mail market as competitors prepare to defend their territory.

Google said it is also working on an anti-virus scanning feature for Gmail, possibly licensing an existing technology. A new HTML interface will make Gmail compatible with browsers that don't support JavaScript.

Other possible extensions include WAP and XHTML to make the service as widely and easily accessible as possible. "We want to make it the best e-mail service in every single dimension so you have absolutely no reason to use any other," said Georges Harik, who is in charge of new projects at Google.

While the POP3 support is an important feature to have, Gmail still needs calendaring and schedule-management features - offered by competitors - said Teney Takahashi, an analyst at The Radicati Group. For example, Yahoo's Web mail service offers a calendaring system that integrates with various versions of Microsoft's Outlook.

"Right now, Gmail is very good at managing mail but I'd like to see the service extended to other areas of your daily life: managing your schedule and possibly being able to synchronise that with your desktop client, like Outlook, would be very valuable," Takahashi said.

While Gmail users are served text ads that appear next to the messages' body text, ads will not appear with messages that are downloaded via POP3 to the client e-mail applications, a Google spokesman said.

Another claim from Harik: "We intend to develop the best spam filter in the industry." You'd be right to be sceptical but at the same time, Google has an uncanny ability of getting things right.