I've just had a Design Idea. What if the main window was a scrollable static box? That is, the browser content will not be scrollable, but the text inside a box will be. The Nav box will not be moving at all, of course. If anyone is interested in seeing this, I can make it happen for some 24 hours - just tell me (if comments aren't working please use email). In TM2, this behavior will be configurable (customizable box size, location, scrollability, color, border properties).