I would guess that the table in the video has capacitive proximity sensors.
Here's an app note on capacitive sensors:
http://www.analog.com/library/analogDialogue/archives/40-10/cap_sensors.html

- Nick



--- In sensorforum@yahoogroups.com, "blazinlyfe42" <blazinlyfe42@...> wrote:
>
> I'm going to make a beer pong table and I want to have led sensors on where
the cups are suppose to go. i want it pretty simple, only 2 colors or just have
the LED turn when i remove the cup. I got the idea from this video.
>
> http://www.youtube.com/watch?v=CL1y27ucicY
>
> Thank you!
>