Google Wave is being on of the hottest tech trend around the world right now as it said to be collaborative in real time.Here are some link where you can try to get Google Wave invitation. As the test version it is limited to only 100,000 users only.
2. Google wave federation protocal
3. Google Wave Developer Sandbox Account Request
If you want to see how it looks like you can see it as follows:
Here is another one from CNN