Choire writes in with another foodie suggestion:
what you REALLY want to do once in your life is make your own "mother sponge" — capture some wild yeasts outside, and blammo, you've got your
own tamagotchi, basically, which needs feeding and care. it really only takes a week to raise before it can go dormant in the fridge, with weekly feedings– and it makes REAL sourdough, not that blechy SF sourdough. and any good baker should do it once. it's both incredibly easy and incredibly hard, but REALLY the most satisfying bread experience EVER.
It sounds scary, but I'm going to trust him on this one.