Take a look at the tabs from the new Firefox 3 Beta. Not only are the tabs smaller in size than in previous versions (and thus creating a smaller target), they have foolishly added borders around them (which aren’t clickable), making the targets smaller still and far more difficult to hit. The vertical borders between tabs are no big deal, but needlessly adding the border below seems a poor design choice. As crazy as it sounds, we could use those 2 or 3 pixels of height for the tab, because it will make using them much easier.
Since when do tabs peek down from above anyway? I’m all for experimentation, but let’s be reasonable.