Want to check e-mail, listen to music, browse the Web, check your calendar or get directions on the go? Look no further than your cell phone. But not any old phone will do. To really tap into the possibilities, you need a smart phone.

What makes a smart phone "smart"? Like a computer, it has an advanced operating system. This allows a cell phone to have many features similar to those of a personal digital assistant, or PDA. Such advanced operating systems are made by Microsoft, Palm and Symbian.

So if you're in the market for a new cell phone, consider how you might use a smart phone, such as the ubiquitous BlackBerry. It may be a better and more productive choice for you than a trendy Motorola Razr.

For example, say you need to e-mail a sales proposal that's saved on your laptop. Unfortunately, you are nowhere near a Wi-Fi hotspot or a phone line.

Since your smart phone is capable of sending and receiving data, it also may be able to double as your laptop's modem, using Bluetooth or a USB cable. This process is called tethering.

Tethering can take several steps to set up. And your wireless provider may charge extra for it. But it could mean making an important connection, one your business competitors lack.

The ability to take photos and video is almost a given with smart phones. But the quality of the images for the most part is still not that of a low-priced digital camera. Here's where there is another difference between a regular cell phone and a smart phone.

After taking pictures with your digital camera, you may be able to insert the camera's memory card into the smart phone. This can come in handy for more than pictures of your kids. Realtors, insurance appraisers, contractors and other mobile professionals can show clients digital slide shows, and if needed, e-mail pictures directly from the phone while in the field.

Some smart phones come with preinstalled image viewers and organizers. If yours didn't, SplashPhoto (www.splashdata.com; Palm, Windows Mobile, Symbian; $30) and Resco Photo Viewer (www.resco.net; Palm, Windows Mobile, Symbian; $15 and up) have free trials.

With the proper software, your smart phone also can help navigate the highways. For Windows Mobile units, there is Microsoft Pocket Streets 2005 (www.microsoft.com; $25). It displays maps of thousands of North American cities.

The Palm GPS Navigator (www.palm.com; Palm; $249) is a pricey add-on. But it has maps of the United States and Canada and gives voice-guided directions. This way, your eyes never leave the road.

By the way, if you find yourself lost without any of these products, instant help is available through Google SMS. Send a text message to 46645 (GOOGL) with the to and from address. Google will text-message back with directions.

For example, say you're in Washington and want to go from the White House to the John F. Kennedy Center for the Performing Arts. Enter the following text: To 2700 F Street, NW Washington DC From 1600 Pennsylvania Avenue Washington DC. Google will text back the directions in seconds.

As smart phones become more like computers, we will find new uses for them. Some can download and display TV shows. Your initial reaction may be, "Who needs that?" But that is the classic reaction to new electronic products. History has shown that most of us eventually want, if not need, these new advances.