Shoutbox

One single time, my daughter left her msn open and I was able to review the chat she had that evening. I don't know how - it just happened. (Now, before everyone jumps on my case, I generally don't snoop per se but rather, when the opportunity presents itself, I take advantage of it.) It was an eye-opening experience and we were able to have some discussion around some issues that she needed clarity on. I have never figured out how to do this type of thing since then.
In my internet search, I see there are programs you can install to do just this thing.
My question is, does this capability exist already and, if so, how does one access it?
Thanks kindly for any assistance in this effort.