I personally really like pvp and i bet a couple of other people did to. I know making the whole world pvp would create problems so I am suggesting this plugin http://forums.bukkit.org/threads/sec-ge ... ost-714443
if this does get implemented, i would love this plugin along side it: http://forums.bukkit.org/threads/econ-f ... 060.26215/
I've played on several servers with this plug-in. With some of the permission systems, there's a glitch that allows non-PvP players to kill PvP players. Basically, if you're PvP, an arrow will do damage no matter what it's source is. If a non-PvP player shoots a PvP player, the PvP player takes damage and cannot fight back. This, generally, causes all sorts of drama. It's something to consider.