Via Yahoo News:
Google and Yahoo have touted SMS-based searches as an alternative to paid voice-directory services from phone companies.
With SMS-based searches, users send the service a text message with their location and what they’re looking for.
The service then sends back a list of results, often with phone numbers the users can click to call directly.
SMS searches appeal to young cell phone users, says Charles Golvin, an analyst at Forrester Research. Via SMS, Google sends mobile users everything from driving directions to weather forecasts.
In most cases, carriers get a cut, charging a few cents for every SMS sent and received.