Found what you want... (Score 3, Informative)

1) These are available from Brookstone for $150...

2) Delcom Engineering has a "USB Visual Signal Indicator". This includes RED, GREEN, and BLUE LEDs, Piezo buzzer, 2 meter USB cable and USB powered circuit. The cost? $69.00 each... All you need to add is a globe...

If you want to play around with this stuff, Delcom Engineering also makes USB chips, cables, etc. and they make USB development board for $49.00 that you could you could use to build what ever you wish...