Haven't been playing too much Minecraft online but starting a new world with the new "rules" (no item spawning?) would be ok for me.

About EvilSOB's idea: maybe its really not good to be able to find the ip via google search. Everybody who is interested to join could post his Minecraft log-in name in this thread and would get the IP via PM.
BUT (!) this is a lot of administrative work, and I can understand if you (Michael) don't want to do this.