just-ping is a very fast, simple & useful web application.  It’s used to keep track of web sites and see if they can be reached from 26 different regions throughout the world.

I’m not sure how much I will use it, but I suspect there will times that I’ll be glad to have it in my bad of tricks.

Also, check out their other application: just-traceroute. It runs a network traceroute command from 4 different locations around the world.