edit: I overlooked a simple checkbox.
Just upgraded from Firefox 1.5 to 2, and Tabbrowser Extensions don't work anymore. I found Tab Mix Plus, which is almost as good. [Edit: cut, snip, delete.]
I just found the MileWideBack add-on. Just slam the mouse to the left edge of the browser page and scroll up or down to cycle between tabs, or middle-click to close a tab. Unless the cursor is already positioned over the tab bar, it's probably even faster and more convenient than having to accurately position the cursor along the bar.
Waitasecond. In the pursuit of further speed and convenience, how about if the user could just right-click-and-hold and scroll or middle click to do what MileWideBack does? Can anyone think of a problem with this? When I right click there's no menu until I release. With an extension, if I scroll or middle click those actions would cancel the menu from appearing. Or does this already exist too?