A new service being rolled out by AT&T, Verizon and Alltel will let you hail a taxi by dialing a shortcode message. Better hope you're not in a hurry, though.Sometimes flagging down a taxi is impossible. You stand there forever with your arm in the air, fighting off cramps in your shoulder in attempt to catch the attention of a passing taxi driver. CellWand and its carrier partners are offering subscribers with another, less cramp-inducing method: Your cell phone.

If you dial in "#taxi" and hit send, the service will connect you to a local taxi company serving whatever area you happen to be in. I am in San Francisco at the moment attending the CTIA Wireless show, and decided to give it a spin. There were numerous taxis going up and down 4th Street outside Moscone West. Flagging one down shouldn't have taken more than a few moments. Even so, I dialed in the code. An automated attendant asked me what city and state I needed a taxi in. I told the service, and it then connected me to a local cab company. You don't get any sort of choice about what cab company it connects you to.

In the end, the dispatcher was able to get a taxi to me in 10 minutes.

Given the ready availability of taxis on the streets of San Francisco, this process took far longer than holding out my arm would have. But there are times when you want to call ahead for a taxi, such as when you need a lift to the airport. Using something like this new service would work perfectly for that, because it saves you the hassle of breaking out the Yellow Pages or searching the Web for local cab companies.

The one hitch is that the service isn't free. AT&T will charge users $1.79 per call, and Alltel and Verizon customers will be dinged $1.50 per call.

Still, it is a simple way to get a taxi when you're in need.