Has anyone used the:
SainSmart 8-channel 12 V USB Relay Board Module Controller for Arduino?
They are advertised on Ebay for $50-$60. Not a bad cost, if you could really remotely locate an output block 6 to 10 feet away from your primary arduino controller....and just supply the output block with 110/220V to power your outlets, (have a built in 110v to 12v power supply to power the usb relay board) and a USB capable to send the On/Off commands. 4 is an even better number as you could be more assured users won't overload the circuit sourcing the 110v, but I like the 8 outputs, because you might as well have more available if you go through the trouble of a power supply, enclosure, power cord, etc....
I ask because I see the For Arduino in the Title, but I do not see any mention of sending commands to it from an Arduino in any of their specifications.