TL:DR; MP4 To MP3 is an easy, efficient, fast yet free MP4 to MP3 converter.
Download MP4 To MP3 Freeware - Rating: 4.41
Video Converter 2005 is more than a simple video converting tool, convert your videos to 3GP or QuickTime, Avi or MP4. Extract the sound track to MP3 or Ogg or WAV, grab JPG images of your favourite video, see all your videos on your 3G phone or Pda.
Video Padlock is easy to use encryption software that allows you to protect any file on your PC, especially downloaded videos. Create a master password, choose the files to encrypt and clcik a button. The files become secure - only viewable by you.
FLV To 3GP Converter is a very easy to use conversion software. It can convert almost any file with FLV extension.