It's a lite but powerful application that will convert your videos in 3gp format, the one supported by PSP and most mobile phones.
You only have to choose the output format - it offers more than 20 formats- and drag and drop the video you want to convert. The time it takes to convert the video depends on its length.
In addition, 3GP Converter includes some profiles for certain formats such as SD-VIDEO or 3GPP + AMR whose only goal is to optimize video size without losing audio and video quality.
Finally, the program doesn't need to be installed and although the original language is Japanese, you can easily change language into English in the main window.