How many times you've launched a search in Firefox by using the search box (located on the upper right corner) and the search box size was not enough to contain all your text?
I've discovered this great Firefox extension, called (with fantasy 
) ResizeSearchBox, that adds a resize thumb to the toolbar which can be used to resize the search box.
Now I'm asking why these types of features, really simple and really useful for the end user, are not present on the actual Firefox release... I hope for the future!