First, let's look at the fun uses for a two way radio. We all remember when we were kids and there were walkie-talkies (depends on how old you are, I suppose!). We would run around and talk to our friends, pretend to be spies, pretend to be the police, or pretend to be war heroes. Possibilities when children play ?pretend? are endless, and limited only to their imagination!
Don't underestimate how special it is to a child when you let them use something normally intended for an adult (like a two way radio). It makes them feel valued by you, that you trust them. Tell them, when allowing them to use electronics such as a two way radio that this is a test to prove that they can take good care of something. If they take good care of the two way radio, then you'll trust them in the future with other fun stuff, sometimes expensive things.
The helpful uses for a two way radio are many. One example is when a husband or wife is working on a project in the garage, and the spouse is inside the house. The two way radio can act as a portable intercom system (although two way radios are much less expensive than an intercom!). When dinner is ready, or when help is needed inside the house, one spouse can alert the other on the two way radio.
Another helpful use would be when the children are nearby but not within eyesight or earshot. Let's say one of your children goes for a bike ride with their friends. It would be unreasonably expensive (and risky) to buy a cell phone for a younger child and expect them to take good care of it when they go out and play. That doesn't mean you can keep tabs on them.
With the two way radio, that bike ride is safe. If they wipe out or get a flat tire, they can just call you on the two way radio. If dinner is ready, you can page the child. When it's time to check in at a certain time, they could be down the block playing in a friend's yard and they could check in using the two way radio. If they forget to check in, you could check up on them with the two way radio.
As you can see in the last example, a two way radio can be a tool that could potentially put your mind at ease or even save a life. Another use is if you have a friend or family member who is disabled. Again, the two way radio can act as an intercom if you live with this person (or live nearby, depending on the range of the two way radio). A single push of the button is much quicker than a phone call in an emergency.