CNet points us to the Belkin Conserve Surge Protector which shuts down 6 of its 8 outlets completely with a remote switch that you can mount by/like a lightswitch. The idea is pretty simple but can you make it work? A lot of devices require always on-functionality. Cable Modem, Router, etc. Plus, all Macs are pretty good about going to super low power mode when idle so is the cost savings worth it?
On the other hand, devices like lights, printers, TVs, and some computers and peripherals can be shut down to save a buck or so a week. Oh, and Amazon has the device at a very friendly $25 after $10 Belkin rebate.