Any Video Converter
Any Video Converter has a simple, easy-to-use graphical interface to convert between popular video formats. Any Video Converter is especially useful for converting downloaded FLVs of YouTube videos into a more usable format.
Handbrake
"HandBrake is an open-source, GPL-licensed, multiplatform, multithreaded video transcoder, available for MacOS X, Linux and Windows."
Free Video Cutter
"Free Video Cutter is a free video utility to help you to cut and split your video files into small size you can use it as a video cutter, video splitter or video clipper".