With my giant, god-like foot I would kick slow drivers forward. If they don't get the hint, I would reach down with my giant god-like hand, pick them up, and put them down on the side of the road until all other traffic had passed.
People who drive too fast and/or tailgate would wreck their cars, but they themselves would not get hurt, nor would anyone else.
People who park their carts in the middle of the grocery store aisle blocking oblivious to everyone around them trying to get by would find their cart simply vanishing so that they'd have to start their shopping all over.
Waitpersons who ask me "how is everything?" right after I've taken a mouthful of food would suddenly find the partially-chewed food in their mouth, and I'd say, "I don't know, you tell me."
People who try to talk on cell phones while driving will have their cars break down.
People who try to text message while driving will go blind, so that they can neither drive nor read.
All doctors will at some point in their lives develop a condition that cannot be verified or identified with any known medical test, and their doctor will tell them that there's nothing wrong with them, or that "it's just stress."
All emergency room personnel will become patients at the emergency room where they work (not all at the same time), and their colleagues will treat them like any other patient. The hospital will charge them hundreds of dollars just for being there, the labs will charge hundred of dollars for tests, and the doctor will charge hundreds of dollars for a examination lasting less than 5 min. The insurance will pay, at most, 80% of the fees, but only after a $75 co-pay and a $100 deductible.
I could probably go on and on, but I should stop before I go mad with power.