There are now more than 190 million cell-phone subscribers, more than one per household, on average. A small but steadily growing number of people use a cell phone (a.k.a. a mobile phone) as their only phone. Phone manufacturers and wireless-service providers are promoting new generations of equipment that let users do much more than merely make phone calls.

Despite its popularity, wireless service has a reputation for problems: dead zones, where you can’t get service; calls that inexplicably end in midconversation; inadequate capacity, so you can’t put a call through when you want; hard-to-fathom calling plans; and errors in bills. Problems like those are why one-third of the cell-phone users we’ve surveyed say they’re seriously considering a switch of carrier.

Switching is now much easier than ever, thanks to the government mandate on local number portability. However, keep in mind that the phones themselves aren’t portable. If you switch carriers, expect to buy a new phone.

WHAT’S AVAILABLE

The cell-phone itself is only part of what you need. You also have to sign up for service with a wireless provider and choose a calling plan. You can find phones in many outlets, including independent wireless retailers, electronics stores, and Web sites.

The providers. The major national companies are Cingular (which merged with AT&T Wireless), Nextel, Sprint PCS (which is in the process of merging with Nextel), T-Mobile, and Verizon Wireless. There are also numerous local or regional providers.

You’ll often find phones described as tri-mode, dual-band, tri-band, or multi network. Those terms describe the ways a phone can connect to one or more wireless networks. Here are the specifics:

* Tri-mode phones can access a digital network in two frequency bands and older analog wireless networks.

* Dual-band phones can connect to a digital network, but in two different frequency bands. GSM providers often use the term 850/1900 MHz instead of dual-band.

* Multinetwork phones are compatible with more than one digital network, often in two frequency bands. Some can also access analog networks.

* Tri-band or ‘World Phones’ operate on GSM networks in both the U.S. and abroad. Those with 850/1800/1900 MHz capability can operate on two bands domestically and one internationally. Those with 900/1800/1900 MHz capability operate on one band in the U.S. (1900 MHz) and two bands internationally.

The calling plans. Most providers offer a range of plans based around a “bucket” of calling time minutes. The more minutes in the bucket, the more the plan costs you each month. However, the total number of minutes isn’t the most important figure. Some of those minutes may be good anytime, others available only on nights and weekends; if you exceed the allotment of minutes, you’ll be charged 35 to 50 cents per minute, depending on the plan. Cingular, alone among the major carriers, lets customers roll over unused minutes to the next month. Most plans require you to sign a one- or two-year contract and levy a hefty fee if you want to cancel before the contract expires.

Prepaid plans can be a good alternative if you’re averse to a long-term contract. Many wireless providers, as well as Virgin Mobile, Liberty Wireless, Metro PCS, and Tracfone, offer prepaid calling. You pay in advance for airtime minutes, which typically last 45 to 60 days before they expire.

The phones. Some are simple rectangles with a display window and keypad on the front. Others are curvaceous or have a flip-open cover to protect the keys. The major phone manufacturers are Audiovox, Kyocera, LG, Motorola, Nokia, Panasonic, Samsung, Sanyo, and Sony-Ericsson. Light weight is pretty much standard. All the newer phones can send and receive text messages up to 160 characters long to or from any other cell-phone user, and most phones now come with a full-color display. You’ll also see phones that can play popular computer games, are integrated with a digital camera, offer wireless Internet access, or that are combined with a personal digital assistant (PDA).