If not, it's most definitely high-time we did. Having a nice, easy to read graph of all the systems in our network and the memory/cpu/disk load, etc would help us be more proactive with finding and hopefully isolating problems before they get out of hand.
At my last employer we were quite fond of Big Brother. Have a look at this example live status report. It's quite extensive in the components it monitors, and if it's not monitoring something we want, there are plenty of extensions and plugins readily available. (for some reason I'm getting a DNS error when I try to pull up this page from work.) The system can also be set to email (and thus text message) someone when there are major problems.
And of course, the source code is available. I'm unclear as to how licensing would work with LiveJournal, as in if we would really need to buy a commercial license or not.
So, what do y'all think?