Bukkit

Paging system to get the attention of another user

Basic NPC plugin

Apply potion effects to all players permanently

Smite a player, specific coordinates, or where you are looking at!

Broadcast a player's coordinates to all players on the server.

Repair your anvils in style on an anvil with this simple to use plugin.

Add custom recipes to Bukkit via a simple config interface.

Teleportation gates with selectable destinations

Limit the amount of mobs by type within a certain radius to prevent server lag

Basic NPCs as statues that will look at you.