Is my site down for everyone or just me?

I couldn't believe my eyes when I saw an article in the NY Times last weekend - this site is so useful to webmasters, web designers and companies with a website (so everyone): downforeveryoneorjustme.com

I don't know how many times in the past I've had to explain to clients who had inferior web hosting services that their website was live for the rest of the world, just not them. And, now, webmasters can point to a website so people can check for themselves - whew!!

So many people expect that the internet is always "on" but now there are so many moving parts and providers - so many links in the chain which can brake such as a domain server going down (no domain name, no website), internet host server going down, internet provider problems, etc.

Thank fortune for downforeveryoneorjustme.com.