Here's an Applescript I'd rather not lose that allows one to, say, rotate movies they take with their digital camera when they're using it in "portrait" mode.

set originalMovie to choose file with prompt "Select a movie to rotate:"
display dialog "Rotate clockwise or counter-clockwise?" buttons {"Clockwise", "Counter-Clockwise"}
set turnChoice to button returned of the result
set saveRef to choose file name with prompt "Save a new copy of the movie here:"
tell application "QuickTime Player"
    open originalMovie
    tell movie 1
        if turnChoice = "Clockwise" then
            rotate right (the first track whose kind is "video")
            rotate left (the first track whose kind is "video")
        end if
        save in saveRef as self contained
    end tell
end tell