You can also open a tnreimal, type something to receive a path (i.e. cd ) then drag the icon from the top of a Finder window into it.The same thing works in Gnome if you drag the word Location from Nautilus into a tnreimal.
You can use tiger player or media player classic to preview unfinished downloaded torrent videos...Obviously you need to rename the file to remove the bc! from the file extension so for example video.avi.bc! becomes video.avi, then open with media player classic or whatever you prefer and BAM! Bob’s your uncle :)