A common misconception I seem to come across with parents regarding the internet and their children, is that the biggest danger is strangers finding out their child's info somehow. I often hear parents say "oh, his/her name and address aren't anywhere in their profile" or things like this. Nevermind they let their child post photos of themselves (myspace.com is the WORST for this), often in revealing clothing... but they fail to realize the huge danger is your child TELLING a "stranger" their own information. No matter how smart you think your child, preteen or teen is - they will EASILY fall victim to wanting to look cool and not like a scared kid.
In my 20s, I can't even count how many times kids between 12 and 16 would come into internet chat rooms and either say extremely sexual things and flirt with sometimes 40+ year old men, or beg them to let them come over and get drunk. It was downright frightening. I would even ask these kids where their parents were or why they were online unsupervised. Usually the kids would react in anger, stating "MY parents TRUST me!" *sigh* They were too young to see the irony in that statement.
I'm not familiar with the workings of MSN Messenger. If it is a program that does not allow you to enter chat rooms, and you keep note of who everyone is on your child's friend list, then perhaps it would be an OK way for them to communicate with their existing friends. I agree with the above posters that recording information & conversations (as nosy as that sounds) is also a good way to know what your kid is up to.
My bottom line for allowing your child to be on the internet is this: would you drop them off at a singles bar at midnight by themselves and be ok with it? If so, then by all means, let your child have completely private internet access.
