CraftBook adds a number of original gameplay elements to Minecraft from switchable bridges to elevators to gates (including flood gates)! It also has redstone support, allowing you to wire up pumpkins and use integrated circuits!
It is Minecraft's original redstone and mechanics mod for SMP, and the first to bring minecart sorters, named minecart stations, integrated circuits, toggleable areas, and a ton of cool things to Minecraft.
You must be at least an Advanced Member to use this.
Command information can be found here http://forums.bukkit.org/threads/mech-craftbook-3-0-alpha1-redstone-bridges-gates-minecarts-ics-soon-more.6250/ here http://forums.bukkit.org/threads/mech-falsebook-0-79-craftbook-for-bukkit-over-50ics-gates-minecartcontrol-etc-548-579.7227/ and here http://craftbook.sk89q.com/wiki/Usage .