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If you do any kind of video on your Mac, and lets face it, who doesn't, you will need this application. Pretty much converts anything to anything as far as video codecs go. "MPEG2 Works 4 Advanced" is also a good one that this company provides. It's shareware so the most you will spend on it is $25. With all the digital cameras out there taking movies now, apps like this one are an essential part of your toolbox.