It’s always funny when animals act like humans. I once knew a dog that had a charge account with the Good Humor man (that’s the ice cream truck if you’re from somewhere where they don’t have Good Humor). We lived on a cul de sac at the bottom of the hill. In the summer, the dog (if I remember correctly it was a collie) was often outside alone (cul de sac, remember; no leash laws back then). The Good Humor man would drive into the circle, stop his truck and ring the bell. If the dog was loose, he would come running. He’d wait while the Good Humor man unwrapped a Popsicle, then take off to his own yard and slurp it down.
Every few weeks the owner would come out and settle up. They were an older couple with no kids, so they spoiled him. We tried telling the Good Humor man the dog wanted to treat us all to ice cream but, of course, he never believed us.
My dog Darwin (see userpic) is nowhere near as smart as the cat who takes the bus, but I am pretty darn sure he could learn to associate a bell with food. Of course, nowadays it’s not safe to let a dog run loose, but if it were, I’m sure Darwin would learn what that jangle-jangle meant really soon.
My two cats also know what the rattle of the food dish means, but i have to say they are much more discriminating. Unless it's something like tuna or chicken, they don't get nearly as worked up about it. With Darwin it's more like "is it edible?" than "Do I want to eat it?" The two questions are the same to him.
If I succeed in uploading the picture, you'll also see my younger cat, whose name, improbably enough, is Carbomb (named after the drink, not the explosive).