It’s still in beta but I find it indispensable. You tell Google where you live. Then you type in what you are looking for locally — say Indian food, or passport photos, or chair rentals — and then it gives you the shops and services in your area, with links, displayed on a map. You can narrow the range you want to travel. That’s where most yellow pages stop, but Google Local goes further. Like in Froogle, you can type in very specific items like balloon helium, or garden topsoil, or ski boots — not just the thousand common headings found in the yellow pages — and Google Local will steer to you it in your city or county. (It still has trouble finding products by brand in a store, but maybe it will someday.) When you click on a source, Google gives you the reference pages on why it suggested that company, which is often helpful in evaluating whether they do indeed have what you want. Unlike the yellow pages, they include all stores,not just paying clients (although they have advertisers, too) so you get a much broader selection. It is not foolproof by any means, but it is now my first stop for local shopping.
[Since the publishing of this review, Google Local was renamed and integrated with Google Maps. Also worth seeing is Google Places, which lets you create new business listing(s), by location. -- SL]