As for monitoring your childs internet use, you can download a program called KeyLogger, just do a GOogle search for it.......its available as a free download. It can then be installed and will log every keystroke done on your computer, and it can be hidden so your child doesnt know its on there. So you will be able to monitor what they are typing on MSN, or any website that they visit (please be aware that it will record ALL keystrokes like backspace and space, so it will take a bit of deciphering!). We have it installed on both our home comp and laptop to check what sites the kids are visiting, and what they are typing, so that we can monitor the comp's use
Also with this, you will be able to access passwords etc so that you can log into MSN or whatever else they have...a good way to monitor their use on these social networking sites.
Good luck