When I was a boy, I had to walk over to a friend’s house if I had something to tell him. Or I could write him a letter. With a pen.

O.K., that’s a slight exaggeration (there were phones, after all). But children today have a plethora of high-tech gadgets they can use to phone and — more commonly — text with one another. The question most parents have is what type of texting gadget is appropriate for which age group.

Some parents have a very simple answer to this query: None. Cellphones and smartphones are for grown-ups only. But if you feel differently about children and texting (or are finding resistance to youthful communication futile) there are some basics you should know about the devices out there, how they work and how they can be used.

Cat Schwartz blogs about gadgets at HiTechMommy.com. While acknowledging that child-friendly communicators include features like GPS monitoring and unlimited texting — a boon for parents and children — she also sets rules for their use, ensuring that things don’t get out of hand.

When are children ready to text? Schwartz has seen children as young as 6 with their own phones and says that texting is popular with youngsters because it allows them to keep in touch anywhere — from a movie theater, the back seat of the car or the dinner table (though you may take issue with that).

Once the boundaries have been set, however, which phones are best for children?

Most phones can text, but dedicated texting phones are few and far between. Here are a few solutions for the parent who wants to enable their children’s texting habits without spending a fortune on overage charges.

Littlest Texters
While no one is suggesting that toddlers should text, it’s rarely a good idea to even let them play with — or suck on — your BlackBerry. That’s the logic behind Leapfrog’s Text and Learn device. This toy looks like a cellphone and has a qwerty keyboard and LCD screen. Built-in programs run 3- to 6-year-olds through spelling and shape games.

The Text and Learn is about four inches wide and six inches long. It takes three AAA batteries and has two volume settings — loud and louder — which could be a concern. A talking dog named Scout leads children through various activities, giving parents a little time to check their own toys for new e-mail.

The Text and Learn can’t actually send or receive text messages, but it may keep little hands out of your briefcase or purse.

Grade Schoolers
Now for some real cellphones. The new LG Rumor from Kajeet is a texting phone for children, and it includes interesting features that everyone can appreciate.

First and foremost, Kajeet offers parental controls to prevent unauthorized incoming or outgoing calls. The service also includes a WalletManager system that allows parents to add talk time to the service weekly, like an allowance, as well as TimeManager, which limits calls to certain people at certain times. The phone also includes GPS mapping so parents can track children on the go.

Pre-teenagers
Parents who might not want to go the phone route can also look at the Peek Pronto, an e-mail and texting-only device with a qwerty keyboard and color screen. This tiny device looks like a BlackBerry and allows you to send messages from up to five e-mail accounts — Yahoo, Gmail, and Hotmail.

Of course, sometimes just a keyboard and screen aren’t enough. Arguably the most popular texting and phone solution for preteenagers is the T-Mobile Sidekick LX, the latest in the venerable Sidekick line of texting and instant-messaging phones.

The Sidekick has a flip-up screen that reveals a full qwerty keyboard and includes e-mail, texting and instant-messaging support.

The LX is a bit more expensive than these other solutions but it also supports MP3 playback along with social-networking features like direct posting to Facebook, Twitter and MySpace. It also includes GPS services and 3G cellular networking. The phone has a 3.2-megapixel camera and includes a gigabyte of storage space.

Schwartz said that care must be taken to avoid the pitfalls of digital interaction. Seemingly innocuous exchanges can escalate when the parties involved aren’t face-to-face (and are 8 years old, with all the emotion and impulsiveness that implies). Parents may even decide to start snooping on their younger texters.

Parents should also keep an eye on the phone bill to ensure that unlimited texting really means unlimited.  (NYT)