Yet Another Avi Info (YAAI) is one of the best tools to display information about your avi files.
Created by Christian Aichinger
Go to yaai.sourceforge.net
Avidemux is a free video editor designed for simple cutting, filtering and encoding tasks.
Created by Mean
Video Audio Sync Fixer fixs video file that has audio out of sync with the video.
Created by AuDane Software
AVIfrate is an utility that allows you to change the frame rate of an existing avi file.
Created by AM Software