Reviews of the Elgato Turbo.264 HD video conversion add on for Macs, here, here, and here.
Drag and drop any video file into the application and convert it to a high-quality H.264 file in standard or HD resolutions. H.264 video is a universal format that can be played on iPod, iPhone, Apple TV, gaming consoles, selected smartphones, and on the web. Comes with intuitive software and converts videos at amazing speeds. Dramatically accelerates video encoding when the hardware encoder is used with Mac applications such as iMovie, QuickTime Pro, Final Cut Pro, and EyeTV.
Why is Turbo.264 HD necessary? Because the Mac is so slow at converting video files to any one of the dozen or so formats and sizes needed to put video in email, web pages, movies, DVDs. Why isn’t this built in to every Mac?