(Image Credit: Google)

Google delivers everything from your email to your search results to your to-do list, instantly. So why not your groceries, office supplies or your medication?

That's exactly Google's next move, to bring you your physical goods when you want them. In San Francisco, the search giant has began a test-run of its Google Shopping Express service, which provides same-day delivery from a number of stores, including Target, Walgreens, Office Depot, Staples and Blue Bottle Coffee Co.

Using Google's Shopping Express site, users will be able to browse inventory at those stores, put the products they want in their virtual shopping bag, and then select a delivery time that works for them. A Google Express delivery person will then deliver them right to their doorstep.

The catch? It's being called an "experiment" right now and it's only being offered to a limited number of people in San Francisco and the Bay Area. Testers can apply now on Google's Shopping Express site. Those selected will get a free six-month membership, which includes unlimited same-day delivery. Google says it is working out the long-term pricing plan.

"It's incredibly early days and so the service is only available to a small number of people in the Bay Area," Tom Fallows, the product management director for Google Shopping Express, said in a blog post.

Fallows says that the pilot program will expand.

Google joins eBay and Amazon in the same-day delivery service game. EBay's Now service, which provides same-day delivery for hundreds of stores, is available in San Francisco, New York City and San Jose, Calif. It costs $5 per order while being tested.

Amazon provides its Local Express Delivery service in 10 cities, including New York, Las Vegas, Seattle, Boston and Washington. It is more expensive at $8.99 and up, depending on the size of the delivery.