Photography - taking pictures - is a great pastime for young children. It lets them play at grown ups, be creative and explore the world they live in. It also helps with spatial awareness and perspective.
In short, it is a fun and educational activity for young kids - and it's a hobby which most will retain through to adulthood. It's a great activity for all sorts of reasons, and one which should be positively encouraged.
I'm old enough to remember when Polaroid cameras were considered new and exciting. They had been around for many years - but they first hit the domestic market in the late 60's and early 70's.
It was great that you didn't have to wait for your snapshots to come back from the lab. Huddling around the little square photos and watching them turn from black to grey - and then to a recognizable photograph - was an exciting experience (we didn't have games consoles or the internet in those days).
Of course, these days, even a Polaroid is too slow. For all but the most specialized photographers, cameras are digital these days. You can review your photos immediately on a small LCD screen, and have larger versions of your best photos on display on a computer screen, a digital photo frame, or even the family TV, within a matter of minutes.
Apart from the immediate results, there are no reels of film to buy, load and send off to the lab. That makes digital photography a lot cheaper (and more environmentally friendly into the bargain). Neither do you have to worry about running out of frames at the end of a reel - usually just when something interesting is about to happen.
It's a liberating experience. You can experiment as much as you like - and take as many photos as you want. The only limit is digital memory - but the SD cards that usually store digital pictures are very cheap these days, so that shouldn't be a problem.
Take lots of photos, keep the ones you like, delete the rest. For that matter, you can even keep the bad ones - just in case. Just load them from your camera to your computer, or a flash drive and you'll be ready to go and take as many new photos as you like.
As far as young children are concerned, digital photography is, for all of the reasons listed above, a fantastic development. Choose the right digital camera for your children and they will have hours of fun - and it won't cost the earth either.