Google is making a Wave by designing/developing a collborative environment inside the browser. I think it's more like iGoogle but less like it. Well it seems to be an attempt of Google to bring all its product under one hood and give user the power to create and share and recreate media/communications through inter usages of their already exisiting product.
So what's so big deal about it?
Well it's live and real time. So you can see what your friend is typing a message for you.
You may look at the different screenshots of Wave at its official website >>.