Mobile searchers using Google can now search for a product sold by participating retailers just by looking for the blue dots in the search results to see if it's available in a local store.
If there is a blue dot, one can tap on the adjacent "In stock nearby" link and the sellers' page will come up.
An Android phone user can also see how far away the stores are, as long as My Location is enabled or if his location is manually specified.
For those in the US, just go to Google.com in your mobile browser, tap on the "more" link, and then select "Shopping."