Since I opted to move a client's web hosting from eHost.net to Hostmonster over the weekend, I needed to be able to check whether or not the move was successful. After all, since the site would be an exact copy from one to the other, it would look exactly the same whether or not it successfully moved or not.
And since DNS records don't change immediately over the rest of the world (it can take up to 3 days), I needed to know when most of them had changed over to the new server enough that I can tell the client that all's clear.
Enter Host-Tracker. Host-Tracker not only tells you if your site is up or down, it tells you what ip address the URL resolves to. The best part is that Host-Tracker does this using up to forty different servers around the world, so you get a really good idea of whether or not the DNS changes have come across everywhere, not just the one location.
I've been using Host-Tracker since fall of last year, when I was having all of that hosting trouble. It hasn't failed me yet.
Checking this, I knew that hostmonster totally came through in the pinch and the site was ready to go only about five hours after the move. Awesome!