Don't have a phone line available in your datacenter? No problem.
Here's a little trick I've been using...
Check out http://www.enotifyme.com/, you can set schedules, rules ect. When ipMonitor send you a email that something is down we have it copy our email address at eNotifyMe, then depending on our rules it calls the appropriate person or group of people and does text to speach on the email so we know whats going on.
The price alone is cheaper than getting a phone line installed and so far it works great!
eskador, this is really cool! Thanks for sharing!