http://www.paranaiv.no/portfolio/2008/webdesign-sketchbook

May I suggest you don't go there. I believe you, and your client as well, have the ability to visualize the browser space and border.  I do. And if not, who really cares about the design anyway?

Of course, I see a whole slew of designy types rushing to this product with hopes that it will, somehow, enhance their layout.  Not to mention, I am probably underestimating a client's desire to see their website name (complete with http:// lead-in!) written out in the address bar on top... an ego thing.