Comcast has rolled out its Xfinity Home Security Service to six new US markets today, including parts of Philadelphia, Portland, Jacksonville, Sarasota, Naples, Chattanooga and Nashville. Comcast plans to introduce the service to additional US markets before the end of 2011. Initially launched last year in Houston, the service combines traditional security components such as video surveillance and alarm systems with nifty home automation features.

The "Basic" package starts at $39.95 a month and includes 24/7 protection from a "professionally-staffed" central monitoring station that can notify you and/or the authorities about any fishy business. Along with local access courtesy of a wall-mounted touchscreen and wireless keypad, you can remotely enable/disable alarms and view the status of your security system from a Web portal (i.e. anything with a Web browser and an Internet connection).

Folks looking for more than the core security features can upgrade to the "Preferred" package, which includes advanced controls for your lights and thermostat, fire monitoring, as well as the ability to remotely view or record your surveillance camera stream. Naturally, that extra functionality is accompanied by additional controls courtesy of iPhone and Android applications, a keychain remote, as well as text and email notifications for specific situations.

Comcast also throws in a few extra window/door sensors (two versus four) for premium customers, but you'll have to purchase most of the hardware separately if you want fire monitoring, light and temperature controls, and video surveillance. It's also worth noting that the company doesn't seem to offer pricing for the Preferred package, so you'll probably have to call them and get an individual quote, which is common for home security/automation services.