I while ago I introduced a friend to Firefox. I didn’t want to push it but just show it and I hoped it would stick. After some weeks I asked if she liked it and she said it was nice but that she missed the tabs that IE had. I was amazed… Firefox were years before IE with tabs but still it fails… Look at the screen shot from Firefox 3. Nothing tells you the interface is tabbed.
Luckily Firefox 3.5 seems to address the issue. Firefox 3.5 also makes it even clearer than Internet Explorer with a + in the new tab button. Way to go Firefox!