converting AVI files for the iPod Touch

For ffmpeg version 0.4.9 I got this to work (this input file had mp3 audio):
ffmpeg -vcodec mpeg4 -acodec mp3 -i my_input_file.avi -maxrate 1000k -b 700kb -bufsize 8192kb -qmin 3 -qmax 5 -s 480x320 -acodec libfaac -ab 128kb my_output_file.mp4
(this also made the annoying "mpeg4 rc buffer underflow" errors disappear)

A commandline that worked for my iPod Touch:
ffmpeg -y -i my_input_file.avi -b 768000 -s 480x320 -vcodec libxvid -ab 128000 -acodec libfaac -ac 2 -f mp4 my_output_file.mp4