AT&T executive Mike Bennett knows what it's like to get blindsided by a big cell phone bill.

Last year, his 17-year-old son Sean racked up 5,138 text messages in one month, the unfortunate result of natural exuberance over his first girlfriend. The deluge -- the equivalent of 170 incoming or outgoing texts a day -- exceeded his cell phone plan's allowance by some 2,600 messages, and produced a 28-page, $400 phone bill.

The story may be hard for some to fathom but it's one that more parents can relate to these days as texting explodes as the preferred means of communication among tweens, teens and college students.

Households whose cell phone service doesn't include a special text-messaging plan typically pay 10 cents to 15 cents per outgoing or incoming message, an amount that can add up quickly, especially given the way teenagers tend to text in a flurry of one- or two-word messages.

For the uninitiated, text messaging works by using the number keys on a cell phone to type a message that's sent to another cell phone.

In June, Verizon Wireless customers alone sent more than 10 billion text messages, a company record and double the number recorded just nine months earlier, spokeswoman Laura Merritt said.

Despite the popularity, parents don't have to get stung by blockbuster phone bills.

Wireless companies offer cell plans that include text, picture and video messages that generally run from an extra $5 to $30 a month, including packages that allow unlimited messages to people on the same network, such as Verizon or AT&T, or unlimited messages nationwide.

At AT&T, for example, options range from paying an extra $4.99 for 200 text, video or picture messages per month (10 cents for each additional message) to an extra $29.99, which allows all lines in the family to send and receive unlimited messages to anyone nationwide. Mr. Bennett's son is now on an unlimited plan.

Ms. Merritt of Verizon said that because choosing a cell phone plan "gets very confusing," she recommends visiting a retail store to get help wading through the options, especially if parents are giving their child a phone for the first time.

The key to picking the right plan is to find out which numbers the child will be texting most often. If they are mainly numbers on the same network, the plan generally will cost much less.

To avoid being hit with a stomach-dropping bill, Ms. Merritt suggests parents make sure their teens keep close tabs during the month on how many messages they have left in their allotment.

For Verizon customers, the way to do that is to hit the pound key, then type DATA and hit send. A free text message will arrive telling them how many messages have been sent or received during the current billing cycle. (To check talk minutes, hit the pound key, type MIN and hit send.)

AT&T customers can check their message balance by hitting the star sign, punching in DATA, hitting pound, then send.

It may help teens stay under their monthly allotment if it is broken down on a per day basis. For example, if the plan allows 500 messages, that equates to roughly 16 messages per day.

AT&T is planning an announcement next week about a new plan aimed at helping parents control teenagers' bills. Details of the program are under wraps until the rollout on Tuesday, Mr. Bennett said.

For parents who need help learning text-messaging shorthand (if you don't know that "ru" is short for "Where are you?"; "cm" means "Call me"; "gr8" means "great"; and "tinwis" means "That's not what I said," you probably need help), Verizon has a text messaging dictionary that translates English to text and text to English available for free at its stores.

Both Verizon and AT&T also have texting tutorials on their Web sites: www.verizonwireless.com and www.wireless.att.com.

O'Hara resident Jeffry Dunn, a Verizon customer who started texting to keep in touch with his three daughters (ages 15, 18 and 21), said at the beginning the hardest part was trying to keep up with the girls.

"Their thumbs fly over the keyboard. I can't do that," he said.

"I'd be in the middle of answering a question, and they would be sending another one already. That messes up your keyboard, so I would have to start over.

"I've learned to keep it brief if I'm responding."