Google invites users to join Wave

Google Wave, which combines email, instant messaging and wiki-style editing will go on public trial today.

The search giant hopes the tool, described as "how e-mail would look if it were invented today", will transform how people communicate online.

It will be open to 100,000 invitees from 1600BST, each of whom can nominate five further people to "join the Wave".

The tool is also open source, meaning third party developers can build applications for it.

The developer behind Wave described it as "a communication and collaboration tool".

"It struck us that e-mail is still the main communication tool on the web, which seemed remarkable given that it is 20-year-old technology," said Lars Rasmussen, who, alongside his brother Jens, was the brains behind Google Maps.

In designing Wave, the brothers took as a starting point the idea of "a conversation sitting in a cloud".

"We found we could build a flexible tool with a surprising amount of functionality," Mr Rasmussen told BBC News.