FireFox 4 is supposedly just around the corner. I have been using the beta versions for some time now without major problems (besides unsupported extensions). One thing I find annoying however: the keyboard shortcut CTRL+E has been changed from "highlight the search box" to "show tab thumbnails".

Since this is a keyboard command: AutoHotkey to the rescue. The following script captures CTRL+E and sends CTRL+K (the new keyboard shortcut in FF4) instead:

#IfWinActive ahk_class MozillaWindowClass
      ^E::Send ^k
#IfWinActive

Add it to an existing or new AHK file and you're done!