An oft-cited benefit of tabs-at-the-top ala Google Chrome and beta builds of Safari 4 is that they save vertical screen real estate. They certainly feel like they do. After all, the tabs are up in the title bar and the address and bookmark bars are the only thing between that and the web content you're browsing. However, I noticed something interesting today when I had Chrome open on top of Safari 4. See for yourself below.
It's the exact same size vertically, at least on Mac. Whoddathunkit?