Chances are, you don't have the time, the space, the resources, the patience, or an adequate level of geekdom to build a real scale model of the solar system. But don't you wish you did have all those things?
This little calculator gives you a great sense of relative sizes and distances of bodies in the solar system. Unfortunately, you can only start with an adjusted size for the Sun and calculate everything according to that. But it's still cool.
So, if you wanted your scale model Sun to be 3 feet across, your scale model Earth would be about 0.3 inches in diameter, and would have to be positioned 322 feet away. Pluto would sit over 2 miles away.
When I started working in my office a few years ago, we were in the habit of making rubber band balls. So I made two of them into a scale model of the Earth and Moon, and positioned them at the appropriate distance on the opposite sides of my desk. That elicited some weird looks, so maybe you want to do this at home.