The no cellphones idea is great. The no street parking downtown is great.
I'd get rid of all one-way streets (no real reason, I just hate one-way streets).
I'd charge a twenty-dollar toll to drive into the city.
I'd knock down all freeways/interstates leading into the city. They create choke points, divide neighborhoods, and create dead zones in cities.
I'd get rid of buses, but I'd bring back the trolly system, or some sort of efficient and comfortable modified trolly/light rail thing - whatever fits in the best.
And free coffee for bike commuters.