The cell phone as shopping assistant debuted Thursday as Sprint introduced a GPS-based mobile search service that enables shoppers to locate products in 30,000 retail stores across the country.

Also this week, a GPS-based "point and search" service in Japan was upgraded for use in several cell phone handsets.

While the two services are different, they are illustrative of the advanced technological functions that are being installed in mobile phones.

The Sprint service, which was developed by GPShopper and is called Slifter, calls for shoppers to punch in a keyword, product name, model number, or UPC code of a desired product. The service targets the nearest retail store, and availability, price, and promotional information are displayed.

"Sprint customers can use their phones to find the closest retailer to purchase a desired item, without needing to check a phone book, Internet listing or map," said George Ranallo, Sprint's director of wireless data applications, in a statement.

In Japan, GeoVector of San Francisco and Mapion of Tokyo announced their Mapion Pointing Application 2.0 upgrade. The service already receives more than 700,000 daily page views.

Users simply point their cell phones at an establishment -- a restaurant or a store, for instance -- and pertinent information is displayed on the phone's display; restaurants can display their menus, for example.

"Users and advertisers can now connect based on the user's interest," said GeoVector president John Ellenby, in a statement.

The service is available on the KDDI network on CDMA-equipped phones offered by Casio, Kyocera, and Sony Ericsson. A spokesman for GeoVector said a key device in the Mapion service is a compass, which when coupled with GPS technology, enables the service.

"GPS understands where the phone is, and the compass understands what you are clicking at," the spokesman said, adding that the service is likely to catch on as cell phone manufacturers increasingly add compasses to their devices.

The Sprint service is immediately available to the company's data customers for an additional $1.99 a month. Sprint has been in the vanguard of offering GPS applications, including local search and various navigation services.

Large retailers such as Best Buy, Staples, and Toys 'R' Us have listed tens of thousands of product identifiers with GPShopper. According to media reports, GPShopper collects a fee whenever a shopper clicks on a store's product.