Well, finally something about which I feel qualified to add something to the discussion! Beans!
As an vegetarian and mostly organic house w/ two smallish kids, we found ourselves going through copious amounts of organic, canned beans--from TJ's and elsewhere. We were even buying by the case! Then, after very good luck making our own soymilk on a regular basis (see http://www.soymilkmaker.com/ ) we thought we'd try our long-forgotten crock pot...
Long story short: the cheapest, best-tasting, low-salt, perfectly cooked pinto, black turtle and pinto beans you've ever had! AND, we figure the small amount of electricity used for cooking is better than all of the energy to process and can and transport that can from ???. (Yeah, I know the beans themselves were trucked, but hey, we're tryin!)
Want to try it? Three cups cleaned, dry beans of your choice. Eight cups of water. Pinch of salt. Cook in your crock pot on high while you sleep--wake up to awsome beans. It really couldn't be any easier, plus, we've always (usually) got cooked beans ready to rip (!) in the fridge whenever we need them.
I must repeat how much tastier these are compared to any canned bean.
Salud!

Thanks, I'll try a smaller batch in my smaller crockpot ... which only has one speed.

Odograph,
I have two crockpots, one of which usually has a scrumptious batch of chilli con carne in it; the other one alternates between cabbage and potato soup (with soup bones) and whatever else I feel like, such as chicken with organic brown rice.

In the winter time I can keep crockpots outside (covered from inquiring animals) instead of the refrigerator when space gets scarce. One nice thing about my two-crockpot system is that whenever people stop buy unexpectedly, there are always a few quarts of soup for them--that combined with my most excellent homemade bread (organic stone-ground whole wheat flour) makes me a nearly permanently prepared host at very little effort. (Bread freezes very well and can be quickly thawed in the microwave.)

Delicious crockpot food not only can be cheap and nutritious, I have found that it helps me in weight loss, because "real" food is far more satisfying than the typical U.S. junk food diet.