Monitoria is a web service developped by some friends of mine and designed to help you track and minimize downtime on your sites. Excerpt from the homepage:
Monitoria is a website uptime monitoring service designed to help you detect website downtime which can mean lost revenue and profits.
The worst thing is customers who may never return to your website again if they experience difficulties opening your website.
Register now and take control over downtime today!
Let Monitoria monitor your website 24/7/365 and alert you immediately upon your website accessibility, availability or performance problems.
And because you're smart enough to read my blog, here is a 20% discount coupon code: phpmafia20-87361.