Discussion here: http://kune.cc/#!kune.cc/w+1dfj0nkhs1uocHM
For the moment, as there aren't many groups in Kune, a limple list could be added on the homepage so that other groups could be browsed and "discovered".
Another option (requiring more coding I guess): add it to the top right of the screen as a drop down menu.
username | Log out | Create new group | Discover groups |