Comcast iPad Controller -
Comcast's TV Everywhere service incorporates Apple’s iPad as a remote control and information retrieval device. See the demo below.

The iPad interacts with enabled set-top boxes and equivalent devices. This application can be used to control the TV and DVR and can display the television program guide on the iPad. Using the iPad's touch keyboard, subscribers can search through available programming instead of having to do that using a smaller remote control device.

Comcast also has one or more free related applications for the iPhone and iPod Touch. See the demo video: