Today I got a call from the manager of the Wal-mart near by. He was very polite. I had e-mailed about the cart situation mentioned here. He said they were looking into what they could do, other cart systems, etc. but that it was set up at corporate level. At least I've made my voice heard. If enough people mention it, maybe they'll do something about it.
I was impressed that the manager called me back. Come to think of it, the last time I e-mailed a complaint / suggestion to Wal-mart the manager called to let me know they were working on the problem (and they did fix it). I think it was very nice of them, good customer service.