Free AVI to 3GP Converter with Batch Mode Downloads
AVI is the renowned multimedia container format developed by Microsoft for synchronous audio with video playback.
3GP is a video file format that is mostly used for 3G mobile devices but it can also be played on PCs and some 2G and 4G phones.
This set contains some applications that will let you convert multiple AVI video files to 3GP format (batch convert).
All these tools are free to use.