You can use your Google Groups alias as a participant in a wave. This will make the wave
accessible by all members in the group. Also, when you add new members to the group, they will be able to access
all previous waves.
Your group settings will determine who can view the waves sent to the group. If you select
Anyone can view the content, the group waves can be viewed by anyone. If you select only members can post messages,
wave users will have to subscribe to your group before they can interact with your group waves.