Hi All,
I found the below Converter but i think i am missing out some :-
PSP Video Converter for Playstation Portable is a FREE compact GUI tool driven by the ffmpeg and avisynth engines roaring under the hood, which makes all the magic happen Thanks to Nick Swardh
PSPVC :: PSP Video Converter - About
PSP Video Express (Free, my personal best) is a lite version of PSP Movie Creator. PSP Video Express is a video converter that supports video files for optimized video playback on Sony PSP.
Download FREE PSP Video Converter: PSP Video Express
PSP Video 9 is a free PSP video conversion and management application. It can convert regular PC video files (avi, mpeg, etc) into PSP video files, as well as manage/copy these PSP video files between your PC and PSP.
PSP Video 9 - Free PSP Video Converter
MediaCoder PSP Edition ext of Mediacoder . Free as well.
MediaCoder PSP Edition
The full version of PSP Video Express which PSP Movie Creator
DVD to PSP Video/Movies Converter Software
PSPEnc ( as suggest by ben7337)
PSPEnc
3gp converter ( suggested by dukepoth)
3GP Converter | Software - (DivX/XviD) Digital Digest