The Intematic was once sold in Home Depot. For some reason, they and Lowes both started selling Cutler-Hammer (Eaton). Popular in alt.home.automation discussions is Leviton. To have protection without harming X-10 and other remote control signals.
Any electrical supply house will also carry them.
Moving on to more information. Earthing a 'whole house' protector is your secondary protection layer. Every protection layer is defined by the only item that does protection. Every homeowner should also inspect what provides the primary protection layer. A picture of what to inspect:
http://www.tvtower.com/fpl.html