The site design and concept are good. A few things I would change. The body of the site is center, but your header at the top isn't. This can make things look very much out of line on certain browser widths. Also, I am not crazy about the pie chart (logo) bullets for the menu items, makes the menu too busy.
Nice site. Great concept. The interface seems to be simple and straightforward. I think it would be a good idea to monetize it somehow. Maybe sell software from RegNow or something similar.
Cool site... Though I think it might be a hard sell with the installer... Maybe you'd do better in java...