Also, I've read that all(?) cats meow as kittens but wild cats lose the habit as they mature whereas domestic cats retain it and that they don't meow to each other but only to humans.
My two cats actually "talk" a lot to each other, inviting to play, checking each other statuses or indicating their discontent if other is disturbing. Older cat was always making some sounds even when he's alone - he vocalizes just about everything - even jumping down from a chair. Another cat was silent when we've adopted him, but learned to "talk" in a few months, from the older one. That's not exactly meowing - but they're making all sort of sounds. While there's usually a human around, they "talk" to each other even when they're alone.
And I heard two wildcats actually meowing loudly, in deep voices at each other, as they were about to fight. Don't think they were forewarning humans to step aside. ;)
Searched for words for cat sounds and found that there are a lot: http://www.catster.com/lifestyle/cat-behavior-sounds-cats-ma... Then, I guess it's right, I only heard cats meow to humans. I think what my cats commonly use are variations of trills and burbles. Not mewing.
Caterwauling is definitely used between cats, and chattering is a hunting noise.
The meowing is learned behavior. We humans tend to like the meowing and not notice much of the body language, so grown cats, who are raised around humans, meow for us. Feral housecats - like the ones living in barns or otherwise have little to no contact with humans - don't tend to meow into adulthood. These are genetically identical to our housecats.
I never heard it in a zoo though :-)