Check out the Extension Installers guide (
http://code.google.com/apis/
wave/extensions/installers/index.html) for adding menu actions under
'New Wave' that will allow you to automatically add robots/
participants when creating a new wave.
Please note, that guide is out-of-date though, you need to follow this
structure in the XML file:
<extension...>
<menuHook...>
<createNewWave>
<participant id="
your...@appspot.com"/>
</createNewWave>
</menuHook>
</extension>
The 'createNewWave tag is missing the guide and without it you just
get an extra menu item with no action taken.