The minimum horizontal display size without a scroll bar is 640. On an 1024x768 or larger display this allows viewing in a 'slim-line' mode, tall and narrow, which happens to be a very good way to view the site.
All major areas are frames-free so bookmarks work properly.
We do use a frame around the survey and the diversions to make navigation easier. JavaScript 1.2 is used for some non-critical functions. Simply insert your own values between the double-quotes.