Mac OS X: The Mac has a few good and free video converters, but nothing is quite so simple and elegant as Evom. Backed by ffmpeg, it'll easily convert your video to the format you need with very little effort.
While Evom does a great of the standard operations you can get with most apps of its kind, it has a few minor features that really set it apart. Aside from its great, minimal interface it lets you convert video to audio (MP3 format). This is great if you want to use Evom's ability to pull music videos from the web and save the audio directly to iTunes. While Evom focuses on the iPod/iTunes standards, it can also help you create files that are upload-friendly for video sharing sites.