If I was within walking distance of the grocery store, I'd get one of those "granny carts" (what we call them). Like this:
http://www.google.com/products/cata...ct=result&resnum=3&ved=0CFcQ8wIwAg#ps-sellers
We have something similar for the boat that we use to bring stuff to the beach and we've used it to carry stuff home from the grocery store - when there is a grocery store within walking distance. It's GREAT and can carry a lot of stuff with very little effort. I certainly couldn't get a week's worth of groceries for my family of 6 but with 2-3 trips a week, it would be totally do-able.
That's a nice cart (with those front wheels). I'm due for a new cart sometimes (use it mostly for laundry).
If I was in an almost rural setting like yours, just to get to the store, I would like something like this:
http://worksmancycles.com/shopsite_sc/store/html/media/surreysirenettablue.jpg
First saw these at the Billy Graham Central Park rally, where you could rent them at $15/hr but decided to wait until I had a special someone to ride it with. By that time, they were gone, and seemed to be chased out of every place they set up (Long Beach, etc).
However, Hammacher Schlemmer has one for sale, and it's $3700!