We are in the process of taking our network management up to the next level. Our server and network infrastructure has gotten sufficiently large and complex that we need to keep a much closer eye on what is happening. We need to be able to monitor resources, applications, and errors. We need a way to alarm, for example, when a server, switch, or application is down or when a resource gets to a critical range.
We’re currently evaluating What’s Up Gold. I also recently heard about Splunk. Do any of you have any thoughts on either of these or something else we should evalutate?
Clif Guy sporadically 
You gotta check out Microsoft’s System Center Essentials 07 … it’s in RC1 right now.I’ll be bloggin about our results with it in the next couple weeks.Also check out OpManager by Adventnet
I’m in the process of checking out Nagios for the same purpose right now, if you’re interested in an open source alternative, and you have a linux server.
My vote thusfar is for Nagios.I have tried tons and tons of applications for the Vine Network – way back when my private (non-Christian) company hosted over 500K domains – we used NagiosIts open source – and able to be manipulated for your needs… I know you have played around with the virtual stuff – look for a vmware virtual appliance – and give it a whirl.Splunk is used just for reviewing logs and such – great application – expensive – but good 🙂