Coming off recent rumors of a same-day delivery service coming from Google, we now have an official announcement. Google has announced the Shopping Express service, which is being touted as an option to “get the items your order online the same day.” Perhaps even nicer sounding for some, Google is promising to do that “at a low cost.”

While all that sounds good so far, there is one rather big catch. At the moment, Google Shopping Express is nothing more than an experiment that is available only for those in San Francisco. That being said, those outside of the San Francisco Bay Area can hope the trial goes well and we see some wider availability. Of course, that wider availability will likely remain in bigger cities and larger markets for quite some time.

Those who are eligible to participate in the testing will be able to shop with bigger retailers such as Target, Walgreens, Staples, American Eagle and Toys R Us/Babies R Us as well as with with local shops to include San Francisco’s Blue Bottle Coffee, and the Bay Area’s Palo Alto Toy & Sport and Raley’s Nob Hill Foods. Basically, you place your order online and can have it delivered that same day.

Google has said those eligible for testing will need to be located in the San Francisco Bay Area (in the city of San Francisco, and the Peninsula from San Mateo to San Jose). The pricing has yet to be finalized, however Google has said that early testers will get six months of free unlimited same-day delivery. As for future expansion, not much here aside from a bit about how the pilot program will be expanding as they work out the kinks.

[via Google Commerce]