"I too would like to locate a site to house a couple of politically oriented
 discussion lists.  How would I go about finding a server that is open to
 outside listowners?"
 
Well, at the risk of appearing provacative - although my intentions are
strictly the best and purely oriented towards perpetuation of information
and communications - you might consider a Unix site, partially because
of the Usenet's notorious tolerance for *anything*, and partly because
of the growing shortage of VM LISTSERVers able to accept new lists ...
 
Also, you can get a Unix box up and running for under $1000, if you are
willing to skip luxuries, like gigabyte-sized hard disks. Having the
list server running on your home machine gives you a great deal more
control ( and potential for abuse, but that's nothing new ).
 
-- richard