My teen wants a computer in his room

porn sites: legal age verification is very lax
some just have some legal jargon about how you have to be ## age to enter site and a YES or NO button at the bottom of the page or they have a enter your birthday thing which anyone can easily lie about their age

Myspace and facebook: just about as lax as the porn sites, all you need is an email account and a bogus age and you can cyber chat to anyone you can meet.

the best way to protect your child is not to just heavily monitor to see if there looking at porn but to see who they have been messaging via Instant Messengers, email and social networking sites.

IMO- i would rather catch them looking at porn then hear about them talking to a strange who want to meet up for sex.

Edit: you might want to add deep freeze to the computer.

From their website-
Faronics Deep Freeze helps eliminate workstation damage and downtime by making computer configurations indestructible. Once Deep Freeze is installed on a workstation, any changes made to the computer'regardless of whether they are accidental or malicious'are never permanent. Deep Freeze provides immediate immunity from many of the problems that plague computers today'inevitable configuration drift, accidental system misconfiguration, malicious software activity, and incidental system degradation.
Deep Freeze ensures computers are absolutely bulletproof, even when users have full access to system software and settings. Users get to enjoy a pristine and unrestricted computing experience, while IT personnel are freed from tedious helpdesk requests, constant system maintenance, and continuous configuration drift.