There are several ways of controlling an outlet from a PC, but since I had one lying around anyway, I based the project on an Arduino NG i/o board. ($32 from Sparkfun) All other parts were either scavenged, picked up locally at Radio Shack or bought at a grocery store; therefore, there are some messy hacks involved.
Don't let the use of the Arduino dissuade you from attempting this, or a similar problem. The Arduino is extremely straightforward and inexpensive.
Arduino NG - USB Prototyping Board
9vdc 350ma power adapter
USB male A-male B cable
computer power cord (or other suitable grounded cord)
three prong outlet, cover, and box
PC Relay - 12vdc coil rating rs part #275-248
Reed Relay - 5vdc coil rating rs part #275-232
diode (i used rs part #276-1620, but I had it lying around)
Heart-adorned night light
Arduino IDE from http://www.arduino.cc
Xampp from http://www.apachefriends.org/en/xampp-windows.html
ComSender - my serial communications program, php code, and Arduino code. (attached)