Loopt, the US pioneer of location-based social networks, today announced it has started to integrate local advertising that lets mobile consumers tap into offers, coupons and discounts with local neighborhood retailers, starting in San Francisco.

This new functionality is powered by Mobile Spinach, who has built a database of hyper-targeted local offers. These offers can be redeemed directly from the phone, or can be sent by SMS and Email. Besides San Francisco, coverage for major metropolitan areas such as Los Angeles and New York will be added during the coming months.

Loopt, which now claims over 3 million users, is also a partner of NAVTEQ Location Point, the location-based ad network of the digital map maker.