Global Network analyser of your sites?
 

Is there any good global network analyser to check a few times per day the availability/speed of many different sites?

Ie: Someday one of more of your sites gets half the traffic. Everything looks good from the inside but you would love to analyze the site from as many place as possible around the globle to determne the problem. (Local Host, Routing, etc...)

Just pushed 10mbs of traffic to another host....looks okay on local mrtg graph not traffic show a almost 50% dropdown for that day.

I would like to try extertal tools that work around the globle for a better overall analyse of where the problem might be located.

thanks