At Google's I/O event in the San Francisco, the company has given the public a sneak peek of a new system, due to be launched later in the year, called "Wave".

Billed as "what email would look like if it were invented today", Wave combines instant messaging, email and sharing functionality to create a powerful open-source communications tool.

Here's how it works, explained by Software Engineering Manager Lars Rasmussen: "A Wave is a single shared space where two or more users can exchange real time dialogue, photos, videos, maps and documents in what we call a Wave. Everyone can reply to a Wave, people can come and go and you can drag and drop information from all over the web."

That means that it runs in a web browser, but it can also be embedded in sites and you can run your own Wave server using open-source code. There's integration between other web apps like Twitter, and developers can build extensions for the service for users to install.

Interestingly, Wave will only work in modern browsers. IE7+. Chrome, Firefox or Safari are required, but it won't run on IE6. Everything appears in real-time, letter-by-letter, but there's also a "Draft mode" if you like your thoughts to emerge fully-formed.

"Playback" functionality will be offered, so that you can see how conversations have evolved over time, and Waves will be fully indexable by search engines. Like Google Maps, there are not current plans to introduce adverts, but it's fairly clear that if it takes off then context-based ads could be served next to discussions.

We're looking forward to having a play with Wave, and if you are too then you can sign up at wave.google.com.