makes it easy to convert a YouTube video, and all FLV video formats, to MPG4 / AVI / MOV / MP4 / MP3 / 3GP.

This service allows you convert a Flash Video / FLV file (YouTube’s videos,etc) to MPEG4 (AVI/MOV/MP4/MP3/3GP) file online. It is using a compressed domain transcoder technology (outline in Japanese). It converts FLV to MPEG4 faster and less lossy than a typical transcoder.

Want to setup your own Then check out the Open Source project they have released.