It seems very interesting, but there is one thing I do not like, and that is having the menubar on the side. I always feel as though I'm losing so much screen r

It seems very interesting, but there is one thing I do not like, and that is having the menubar on the side. I always feel as though I'm losing so much screen real estate to it. (This is also the reason why I stopped using iGoogle as my homepage) Does anyone have any links to usability research that shows that having menus on the side vs the top is better? It looks like a few people are going this way in their designs, and I am wondering if it is just to make their product look different and new, or if there is actually sound logic behind the changes.