My first post here, be kind 
These machines serve no real useful purpose, but they'd be fun!
Idea one - Lightning tube
Set up by placing glass tubes between two Van der Graaf generators, crafted thus:
Glass tube:
3 reinforced glass in a line
pretty simple
VdG Generator:

tin around refined iron
What it does: when enough current is available to one GdF, electricity arcs through the tube to the other one. Wastes ALOT of energy, 50 EU/tick* length of tube. (so a tube 2 blocks long will consume 100 EU/tick, 3 long=150EU, etc.)
For the Minecrafter who thinks his factory needs more of an insane villain vibe...
Idea two - Lightning Generator (Not a lightning rod!)
Lightning Generator:
Lightning Generator causes lightning to strike random location
within 32 block radius every 5 seconds when powered by redstone during
rainstorm. Consumes 100,000 EU/strike.
Targeted Lightning Generator:
(
=Lapotron Crystal)
Targeted Lightning Generator causes lightning to strike hostile mobs
within a configurable radius. Has a five second recharge time, must be
powered by redstone during a rainstorm, consumes 100,000 EU/strike. (Perhaps it should have hostile, passive, neutral, and anything that moves targeting modes)
Cloud maker:
Cloud maker causes rain when powered by redstone, cost 5eu/tick to
maintain storm, also consumes water cells (I'm thinking 180
seconds/cell)
As I said, they serve no real purpose - except for wasting millions of EU, and making an army of lightning creepers!
Naturally someone is going to say this should be used to turn zombies into (tame) Frankenstein monsters, but I wanted to keep the idea simple to code, as in not mess with mob taming or AI. Perhaps this is more of an addon idea, but I hope you'll consider it, Alblaka. Thank you for reading, and thanks for the awesome mod!