Electric Fences:
I had the idea of fences that damage players/mobs that touch the electric fences. The basic idea is to kill mobs that try to kill you if you are in your base. I think a fence that kills them automatically (because stupid mobs run into it) would be a pretty cool thing because I am getting tired of mobs trying to attack my while I am crafting and even if I have a closed base their sounds can piss me off sometimes
Sure you need EU to power them I think 128EU/t would be fine for them to run. There damage should also be higher than unisolated cable and also they are higher because of the fact they are fences.
My suggestion for a recipe would be:
top: 3x iron fence
mid: copper cable | electronic circuit | copper cable
bottom: 3x iron fence
that would give you 6 electric fences.
I think it could be a nice little addition and iron fences are not really used that often.
Let me know what you think.