Technology and kids - what age is a cell phone appropriate? {Hot Topic}

With technology advancing at the amazing pace that it is, it seems like kids are getting technology younger and younger.  This made me curious about cell phones and what kind of practices parents put into place for cell phone usage and how old their kids were when they let them have cell phones.

I put the question out on Twitter and got a lot of really interesting feedback!

- Some parents let their toddlers play with their cell phones (I do) but mostly for the smart phone features or to talk to people I have phoned on their behalf.  Kids are clearly going to know what to do with a phone at a very young age.

- A fairly common age I heard for getting a cell was 12.  The rules that apply to this are that the phone is owned by the parent and can be monitored at any time.

- Many people require their children's phones to stay on the main floor at bedtime for charging, preventing them from all night texting habits (that definitely would have been me!)

- Some kids have regular phones, not smart, and also have iPods. I've heard of the internet being automated to turn off at 10 or 11 pm to prevent all night usage but still allowing kids to have music in their rooms.

I imagine that my kids will have phones (or whatever they are by then) relatively young.  I'll want to be able to get in touch with them once they're old enough to go out on their own.  I love the idea of spot checks and of them fully understanding that their parents have total rights into their technology. Fortunately I have a few years to figure this out since my oldest is only 5, but I feel like it's an interesting conversation to start having now anyways :)

What do you do? What do you think you'll do? Would love to get some discussion going!