Neighbor videotapes street and says I am speeding when even going 30mph on a 25mph

If you're going 30 mph in a 25 mph zone, you are speeding.  And if he files citizen complaints against you for speeding, and you're found guilty, it isn't harassment, and it isn't malicious prosecution either.  You'll just have to keep your speed down to 25 mph, while you're in camera range;  I can't imagine that this would cost you more than 10-15 seconds, all told, on your way in or out.

Two can play at that kind of game, though.  You can videotape his driving, too, and perhaps there are some other technical violations of law that he's committing.  He isn't doing anything legally wrong by citing you for speeding, if you are, so perhaps you'll have to fit legal nit-picking with legal nit-picking.

Then again, if he tickets you and you can go to court and prove he's wrong, then you start to gain some leverage.  If you can do that twice, then you can probably sue him.