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. When you submit an url, it will download and convert to the video format. Then you can download the converted file. FLV to MPEG4 Conveter engine is now OpenSource.