Rendering lard
OK, I've never done it, but this post over at An Obsession with Food goes into great detail about how to render lard. And I have to admit, I probably never will do it -- I can't think of a single recipe I've made that has ever called for lard. (Remember, I have an aversion to making my own biscuits.) Anyone?
ETA: Upon googling, I see that you can make your own soap using lard. Hm. Christmas gifts for next year ...?