This leads to an interesting variation on Keith Henson's Far Edge Party:
Send out invitations to each star system in the form of basic seeds for
the formation of life. Kick back and wait for a few billion years, in
your galactic core easy chair, and all sorts of interesting and odd
intellegent creatures show up of their own volition, after independantly
deciding that the core is the place to be.
They bring their stellar mass with them, of course, this is a BYOS party.
-PW