Well multiworld is broken because the worlds are run on different servers I assume....
Well this guy was thinking along with right lines
http://forums.bukkit.org/threads/tp-server-port-suite-v12-server-to-server-teleporting-1000.18594/
Glancing through it however it might be outdated/buggy, but if you had any java devs they might be able to fix-er-up. Otherwise the worlds would have to be all in the same server :S
Well this guy was thinking along with right lines
http://forums.bukkit.org/threads/tp-server-port-suite-v12-server-to-server-teleporting-1000.18594/
Glancing through it however it might be outdated/buggy, but if you had any java devs they might be able to fix-er-up. Otherwise the worlds would have to be all in the same server :S