If yout set the preferences to automatically import any downloads into iTunes, you end up with duplicate music files. Is there a quick way to avoid this without having to manually delete one all the time?

Thanks in advance

In iTunes Preferences...Advanced, deselect "Copy tunes to iTunes folder when adding to library"

Thanks Richard but I want the file in iTunes so that I can play it with the rest of my music so I don't want to uncheck that box. Any other ways?

You may just be able to do it using applescript. Else from the command line. Not something I've ever tried.