I was in search for a long time for a suitable tool to convert my video files to 3GP format to be exported into my Mobile Phone. I didnt succeded on Ubuntu with FFMPEG till this day..We should install ffmpeg from the medibuntu repository..But i dunno it doesnt work for me
So I ve to use windows again for this thing Pity..
But happy news is that i still used ffmpeg from net to do this..which is opensource after all 
So what you need to do is pretty simple 4 steps
1.Download & Unzip This File to your desktop
2.Copy the File To be Converted into This extracted directory
3.Run The ‘3GP Converter.bat’ file(Its not virus u can check if u want the source file is provided)
4.Enter the input and output file names
Enjoy new videos on your mobile !!!
