I have googled this and come up with a variety of results, but can anyone suggest one that they have actually used, great if it was free as well  :thumbsup:
			
			
			
				I got this one to work and managed to save a YouTube vid on my Mac.  For free!
http://video.online-convert.com/convert-to-mp4 (http://video.online-convert.com/convert-to-mp4)