There's another version running 24/7 at cownet247.bounceme.net:25564
Rules:
Spawning Ender Dragons will get you banned.
Don't use massive Cuts with World Edit.
Don't grief other peoples stuff.
Always ask permission to build close to someone else's stuff. Use a sign if that person is not online.
Don't spawn large numbers of mobs.
Obey all rules.
Mods:
Precious Stones - another way to protect your stuff.
DuckShop - the easiest shop mod ever.
McMMO - skills, levels, etc.
LaunchMe - Create cannon portals and launch yourself from place to place.
Appleseed - Grow apple trees.
AutoLight - Light up the darkness.
AutoRegionGuard - Guard your favorite places from other players
BOSEconomy - Show me the money!
ChickenBombs - Throw them cluckers and they esplodes!
CommandBook - All sorts of useful commands.
DiscoSheep - Sheep that are rock'n out!
ExplodingSheep - Did you know that 1 in 4 sheep explode when you hit them?
Heroes - Gain experience and skills.
iGates - Create portals of any shape and material.
LWC - Lock wooden chests.
MobDisguise - Become the mob you've always wanted to be.
MonsterBox - Create monster spawners of different types.
Multiverse - Become master of the Universe.
OpenWarp - Create warp points both public and private.
Residence - Buy land and protect your buildings from damage and griefing.
WorldEdit - Yup. Just what it says. Edit the world.
RideTheDragon - Now you can spawn, ride and destroy them.
Information about blocks can be found here.