Just a quick warning: If you're looking for pen-pals, be sure to realise that you can't trust everything that everyone says. Someone that claims to be a child/teen could actually be an Elderly Adult out to get your son. Remember the basic rule: Don't meet up with anyone in real life - only type virtually to each other etc.
That said, I, myself, am aged 14. I'm currently predicted A's for my GCSEs, I was left completely light-headed after watching how brilliant Avatar was in 3D but, however, I'm not too fond of Comedic Movies (Austin Powers and The Love Guru are exceptions) or Horrors. I have huge interests in computing, gaming, The Internet, the Three Kingdoms period of Ancient Chinese history and British Etiquette - yet most I can never seem to apply into a real-life situation. My interest in the internet has made me learn how to create very basic websites on Invisionfree/Zetaboards, My computing/gaming interest has given me a wish to study some form of computer programming language (and, hopefully, become an MMORPG designer in the distant future), The Three Kingdoms period of Chinese history has... Well... Given me an ability to boast about it and my interest in British Etiquette (which I can never apply to real life) has, in my eyes, given me a better ability to judge others on their manners.