
The folks over at Cellphones.Org has a great list of ways to encourage kids to use cellphones safely in their article "11 Ways to Keep Your Kids Safe on Their Cellphones."
Some of the tips given: "Be Respectful in Public," "Don't Disclose Private Information," and "Never Talk to Strangers" are great examples of old-school common sense advice applied to new age technology use. My favorite tip is "Discuss Sexting."
The most common instances of sexting in the younger set involve sending pictures of themselves in provocative clothing or completely nude. It is important that you discuss this practice with your child and let them know in no uncertain terms that it is not allowed and will not be tolerated. If you are afraid to bring this subject to their attention in case your child doesn’t already know what it is, don’t. You can be assured that your child is already familiar with it.
While all parents agree kids don't come with instructions, they can usually look to examples of how to deal with situations using their own experiences or the experiences of those close to them. The proliferation of technologies like cell phones and Facebook has caught many parents flat-footed and wondering how to develop comprehensive rules. Cellphone.Org's post shows common sense applies to new technologies as well.