Parts List:

Radio Shack:
Multipurpose PC Board with 417 Holes: (276-150) $1.99
Hookup wire, Solid, Red, Black, Green, 22 Gauge, 90 ft, (278-1221) $5.99

Jameco:
3 x Blue LED, (183222) $2.95 ea
Green LED, (334473) $1.45 ea
Red LED, (33481) $0.27 ea
220 ohm, 1/8W resistors (100), (107941) $0.69

Sparkfun:
Arduino NG, (Arduino-USB) $31.95

Home Depot:
Lighting Fixture (Portfolio #74457 or similar), ~$10.00

Other Items:
Red Sharpie (Optional)
Blue Sharpie (Optional)
Green Sharpie (Optional)
Black Spray Paint (Optional)
Solder
Soldering Iron
Round cut piece of 1/2 inch wood - cut to the size of the lighting fixture base)
2 x Standoffs Metal Hex (Sparkfun: COM-00126 if you don't have any, which is unlikely)
2 x motherboard mounting screws (that fit the standoffs)