Blipstar is a cool little Web mashup made into a widget. It locates physical stores on a Google map. A business owner goes to the site and enters in the stores' addresses. He or she then gets a link to put on the business Web page. Visitors to the business's site can enter in their location, and the widget will tell them which store is closest to them and how to get there. Here's an example:
Find closest CNET location.
The benefits of the technology are self-evident: If you want people to go to your stores, it's good to tell them where the stores are.
Blipstar is free for the moment, but donations (starting at $25) are encouraged. This is significantly less than other store locator services, as creator Paul Clarke shows on the site.
BlipStar also creates Google Earth (KML) files [example], which make looking at your stores a lot of fun.
It's a nice little tool. If you run a small business with a physical component, check it out. And while you're at it, see Widgetbox, which has other site gizmos you might want to play with.