Internet Explorer 7 can have a side bar (called an "Explorer Bar" because Microsoft thinks that if they don't use everybody else's nomenclature, people might think they had an original idea) which can show, among other things, bookmarks (called "Favorites" because Microsoft has a baby-talk mentality).
Which is good. And on Firefox, I got used to being able to drag and drop to create bookmarks, by dragging either the tab for the page I want to bookmark, or the favicon in the left end of the address bar.
Which is very handy and easy and convenient and lets me choose between five hundred different folders quickly.
On IE7, I can't. Drag and drop for bookmark creation doesn't work for tabs. It works for dragging the favicon, but not the tab. Dragging the tab can only be used to reorder them.
I present this as proof positive that Microsoft don't get tabbed browsing, and only did it because they realised that it was popular.