When you're sitting at a computer, a good search engine puts the entire Internet at your fingertips--but that probably isn't what you want when you are searching from a cell phone. Skimming pages of Google results on a tiny screen with sluggish connectivity can be frustrating, and typing keywords on a small (or software) keyboard is not fun.

New mobile search services and apps let you speak (rather than type) search terms and filter results based on proximity (on the assumption that you're likely searching for something nearby). Microsoft's Tellme, Yahoo's OneSearch, and offerings by smaller companies such as ChaCha may not be perfect, but they do try to tailor their searches to meet the needs of mobile users.

Applications that accept speech input and return Web results are the latest development. New versions of Tellme and OneSearch (available at launch as downloadable apps for recent GPS-enabled BlackBerry devices) let you search by holding down the green Talk button and speaking keywords into the handset. Speech-to-text technology then turns the digitized audio into text fed to searches that use the handset's location information.

Results on OneSearch look and act more or less like traditional links, organized by category. When I spoke the words "dim sum," the first results OneSearch returned (under the heading 'Businesses') were Chinese restaurants and a link to retrieve more of the same. The restaurant listings included links to maps, reviews, and a call dialer; conventional search results, including an entry from Wikipedia, came next.

The new version of Tellme hadn't appeared at this writing (it should be available by the time you read this), but in a demo it, too, presented a list of businesses. Clicking any entry produced a screen bearing the company's address and phone number at the top, with icons for relevant info or tasks such as initiating a phone call, displaying a map, or even making a purchase. If you don't want (or have)the GPS data to guide the search, you can tell your preferred location to Tellme. It does not provide general search results, however.

An earlier version of Tellme, which accepts voice input for directory assistance, is available on Sprint and Helio GPS phones. Or you can try out the lookup service by calling 1-800-555-8355, or text search keywords to 83556. Starting today (April 23, 2008), BlackBerry users will be able to get the Tellme app over the air by pointing their browser at m.tellme.com; alternatively, they can download the app at http://www.tellme.com/you .

Google doesn't offer users a voice search app, but you can submit a voice query to 1-800-466-4411, and be connected to a relevant business. Google also supports a range of SMS searches.

ChaCha, another search service, invites you to dial 1-800-224-2242 (for voice queries) or text your question to 242 242. In an interesting twist, ChaCha uses real people (called guides) to answer some queries. It took ChaCha only a few seconds to tell me the dates of the Democratic National Convention (August 25-28). But a query about new episodes of HBO's John Adams elicited information about the network's series House, which was irrelevant to my search request except perhaps in the marketing sense of "other fine products you might be interested in." Maybe no guide was on duty...

Meanwhile, V-Enable has announced a voice-enabled app for its Free Mobile 411 Web-based lookup service for Sprint users; others can type in keywords and, if they come up empty, opt to connect to a live operator--but in that case, Directory Assistance charges will apply.

Go2 accepts text input only, but its menu-based structure acts as a filter that permits you to focus on restaurants, movies, news, and the like--or conduct a general search.

Mobile search services expect to make money through ads, sponsored results (Go2's restaurant search results, for example, included a link to Zagat's site) and transactional fees (for example, a cut of a movie ticket purchase). Users need only consent to the use of their location information. Since so many of these services are new, it's unclear what impact advertising will have, and I wouldn't want to use them without an all-you-can-eat data plan. But for targeted information on the go, they should prove to be very helpful; for once, Google has some catching up to do.

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