Aremysitesup.com is a free online service that does exactly as the title says. Monitors, for free, your sites indicating if they’re online or not. You can also receive SMS updates with the status of your websites available from what i can see in the US, UK, Germany, Austria, Canada and France. Nice little app but i’d love to see an Air application for the system tray giving me information without having to login on the website. Excellent little thing though.