ive been trying out this mod also......this one is awasome for building security...just stack 3 iron blocks and power them any living thing will be struck but lighning.. great for keeping bad guys away at night while your working on your wilderness home : )

http://forums.bukkit.org/threads/mech-teslacoil-v1-4-keep-mobs-at-bay-the-futuristic-way-766.16115/