While Google SMS (Short Message Service) uses text-only messages to deliver its results, Yahoo's new mobile service offers, maps and Web site that let people point, click and make a call.
The two companies took their most significant steps yet into the cell phone market within a few weeks of each other, showing just how eager the Web search industry is to expand its reach.
During a keynote speech Wednesday at the CTIA Wireless IT & Entertainment trade show here, Yahoo Chief Operating Officer Dan Rosensweig said the mobile Internet industry is at a "tipping point." As mobile use continues to grow, he said, more customers will want access to their Yahoo services.
"The Internet has become essential. The industry is ready, and mobile usage is exploding," Rosensweig said.
But the cell phone industry still poses some challenges to search providers, most importantly U.S. consumers' reluctance to surf the Internet on cell phones. U.S. customers typically prefer to use the Internet over a wired connection, although in Europe and Asia using a cell phone to access the Web has become popular.
However, the mobile Web also represents a new revenue source for Yahoo, Google and other traditional Internet companies. While Yahoo has no plans for display or commercial search ads yet, the company hasn't ruled out commercial search in the future, Yahoo executives said at the trade show.
Yahoo's mobile search is available now to AT&T Wireless, Cingular Wireless and Sprint subscribers. Meanwhile, Google's SMS test product works with the top five U.S. operators. Charges for both services may vary, and depend on individual plans. In general, U.S. wireless operators charge between 2 cents and 10 cents to send messages or download Web pages.