Hi there,
It is amazing how much more there is in the technological world for our kids now, than when we were kids. It has its' advantages, but it certainly has its' disadvantages as well. One of the many disadvantages is that with text messaging, IM, email, etc... our children's outside contacts are becoming more "private" to them. Our monitoring, as parents, becomes more difficult, and we need to become more creative.
It sounds like you have the right idea around setting parameters and boundaries around your son's use. It's admirable for any parent to do that, because it is so difficult in today's age.
One large component of allowing your child access to all of this "technology" is Trust. But even with trust between yourself and your child, there are dangers. And a lot of them.
I am a drug test consultant. I own NorthEast Drug Test Services. (www.nedts.us) One of the things I do, is try to educate parents around one of those "dangers".... that would be DRUGS. With increased privacy in our children's day to day activities, there comes increased access to illicit drugs. Your son is at the perfect age for you to start (if you haven't already) talking to him about drugs, and their dangers.
One of the motto's I have as a consultant, is Trust But Verify. My company offers parents several ways to monitor children's possible substance use. One of those ways is through having a family implement a "family pledge" stating the family position on drugs and alcohol. It's a great way for parents to open the lines of communication between themselves and their children. Another way is for parents to regularly test their children for substance use, with at home kits. My company also offers drug detection assessments, where we can detect the presence of drug residue on any surface.
I'm only mentioning this to you because I am sure you are aware of the potential dangers our children face, which is clearly why you are worried about how to limit and monitor your son's use of today's technology. I'm not sure many parents are aware that the technology to monitor kid's potential drug use is out there. It is much easier to establish parameters and boundaries now, at your son's age, than when they are older.
Good Luck with whatever decision you make regarding limiting your son's use of technology. I would be interested in hearing your decisions, and how it works for you. I have 4 children myself, and I imagine the same battles once they reach your son's age!