Just Uptime is a remote service which allows you to monitor your servers and websites. You can receive notifications anytime to your e-mail, through SMS to your cell phone, CURL notification, and have unlimited contacts. You can monitor uptime, response times, and when you goto your member area you can see uptime and load reports showing you past performance. They do many different types of monitoring including HTTP or HTTPS checks, ping checks, TCP or UDP checks, DNS checks, POP3 monitoring, IMAP monitoring, and SMTP checks. You can change montoring resolution anywhere from every 1 minute to every 60 minutes. Their system checks from different locations worldwide, and can check whether a website should or shouldn't contain a certain keyword. They also offer through their web based control panel uptime reports, response time reports, detailed error log, and notification history. No installation required since its all done remotely.