Idiot parking in my driveway?

No, blocking him in is just behaving like an idiot. Call a tow company and tell them someone has parked in your driveway and you cannot get your car out of your garage and need to get to work now. When his car is towed and he has $150 tow fee to pay, he will not do it again.

Leave a note: "Next time you park on my property, since your apology is clearly meaningless, a tow truck will be called with whose company I will prearrange all paperwork. They will simply come, I will sign the papers and your car will be towed. Your convenience does not take priority over my rights. If this is too much for you to deal with civilly I will advise my neighbors as to my solution as well."

Then DO IT. Follow through but check the laws. Don't resort to false arrest or take a risk with your own freedom.

Yes you can block him in and you should. Let his car sit there until he calls the cops then say you told him not to park there. Even if its a few days I'd let his car just sit there. He won't park there again. Same thing happened to mom during a blizzard and she blocked them in and left her car parked for 2 days

You have no right to block him in, but you can call your local police department and if he's still parked there he can get towed away.

Have him towed. Yes, you can block him in, so long as you don't illegally park to do so.

don't say anything to him next time, just call and have his car towed.

he probably wont do it again after that ;)

you can call the police and have him cited for trespassing. that may also give you the right to have his car towed, or the police may do it for you.

Put a cone in the way. He'll get the message.

You can call and have him towed.