Server Siren 1.1
With Server Siren, server downtime is a thing of the past. It runs as a menu bar item, so a quick glance is all it takes to see that everything is A-OK. If a server goes down, Server Siren alerts you immediately so you can fix the problem and get your site up and running again.
And when Server Siren alerts you, it doesn't fool around. You can set up multiple alarms and be notified by email, by SMS, or onscreen. Server Siren can even run an AppleScript, so you can do just about anything you need to if one of your servers goes down.