The sine wave down the middle of the page helps with visualizing the changing scale. If you want a linear scale, maybe you will appreciate this page: http://joshworth.com/dev/pixelspace/pixelspace_solarsystem.h...
that page lets you appreciate the vast emptiness within which we live..
this link gives some extra details until the page is up http://gizmodo.com/this-scale-model-of-the-solar-system-will...
plus some great links in the comments.