I've seen a couple other redirectors being used...particularly geocities, linkshield, hyperurl, and redirx...in order to "hide" the spamvertized URLs....but I think most of these URL services probably take removal requests more seriously than the spamvertized site hosts themselves; I mean how many reports have you sent to contact addresses in China/Japan/Russia/Romania...? They are still alive

From my reporting experience, GeoCities seems to take down pages within 12 hours of notice (give or take, on the weekends...)
Google is touchy, they don't take abuse reports via e-mail, but have had good success reporting and removing GooglePages spam using the form at
http://www.google.com/support/pages/bin/re...pe=abuse_spam...
Who knows, maybe someone could make a java scri_pt bookmarklet that could auto-fill in the Name, Address fields, leaving us to only need to fill in the URL and paste-in of the full headers...?
Blogspot blogs also appear in spam on ocassion, for them, they want reports filed at
http://help.blogger.com/?page=troubleshoot...Submit=Continue - far simpler form than the GooglePages form

If you are interested in reporting spamvertized domains - you will probably have better luck using the Complainterator program over at complainterator.com - which allows complaining directly to the registrar and name servers allowing these domains access on the Internet.