There is a company out there providing for free, performance monitoring, availability monitoring, and traffic monitoring?  Yes, there is.  Mon.itor.us might have a silly name, but it delivers awesome and free monitoring tools for your web site.

Here is how the web site describes the services they provide:

We provides a “24 x 7″ network and web site monitoring service to help its users quickly identify faults and deficiencies to ensure continuous operations of their IT infrastructure and maintain business operations that provide the ultimate web experience.

From within an Ajax-powered dashboard, you can check server performance and availability, generate uptime reports, track visitors, CPU, memory and other system resources you need to know about.

Mon.itor.us is currently monitoring over 134,000 web sites right now, and I am sure there will be many more to come in the future.