If you've got a personal or business website, it's important to know when it goes down. You can't be around all the time to check on it which is where uptime monitoring services like AreMySitesUp.com come in. AreMySitesUp.com connects to your website 25 times per day and will notify you if for some reason it can't connect.
There's a bunch of services like this available but what we like about
AreMySitesUp.com is that it's free for a basic account and the basic account even includes free SMS alerts in addition to e-mail. Their premium accounts aren't that expensive either at just $25 to $75 US per year if you need more frequent checks, Twitter integration, iPhone Apps, or faster support.