it doesn't cover the real benefits of doing this with ffmpeg. ffmpeg is one of the most valuable tools for any designer who works with multi-media in linux. the true benefits to this guide is that with just playing with these options you can get a handle using ffmpeg to take things apart and than even glue them together.
for example chopping a bumper out of your favorite podcast, taking sound out of a video clip, and many other things. my main use of ffmpeg, but not its most useful, is to have a cron job monitor my podcasts' directory for any ogg files that don't have mp3 files and it than auto-converts them. it also rewrites my rss feeds.
now i just have to get my courage up and actually publish my podcasts... *gulp*