Google Wave has already been termed as the next best thing to happen to social computing and collaboration. Google Wave can be used by those who have an invitation from Google. You have not received any invitation yet and really want to check the service, PyGoWave is what you should be looking at.
PyGoWave is the implementation of Google Wave, the code for which is directly derived from Google’s published Wave API and protocol specification. This will eventually be a full-featured server implementation for easy use, extention and integration with your web servers and applications.
PyGoWave was developed by Hot shot programmers and works and looks just like the real Google Wave and it uses the Google Wave API. Visit pygowave.net and register in it. You will receive an conformation mail and after that login by your username and password and starting using Wave.