I grew up putting this stuff on my popcorn and absolutely love it.  I recently found out that you can also put it on salads that have a vinaigrette dressing and it's also delicious.  Are there other common applications that I am not aware of?  FYI - Brewers/nutritional yeast != baking yeast 
If you have a septic tank, avoid using the garbage disposal, especially for anything like egg shells, bones, coffee grounds, and other things that the bacteria in the tank won't eat.  Worst case scenario is that they can plug up your leach field for a very expensive repair. 