I'm a big fan of NAGIOS. Free and Open Source to boot. (And if you want to pay, you can! Professional support contracts have been available for this and last year IIRC.) Rolling your own monitoring ... [More] system for internal and external uses is so helpful. Not to mention you don't have to worry about giving some external services internal insight into your network. Seriously. NAGIOS. Do it. [edit] Yes, I am aware this post is almost 3 months old. However: No one has responded to it. There was an implicit call for help in the body of the message. [Less]

You can always get a Jabber room and drop in a relay to bridge the two.