Anyone use arduino?

For those who aren't tech savvy it's basically this http://www.arduino.cc/

I've been thinking it could have some neat applications in custom lights/dash/anything electronic.

Could make your tail lights all like a cyclon going back and forth when you brake, or even make tail lights uh, whats the word for it when the light moves etc? Custom fog lights/headlight set up, dash panel with custom interfaces in a LED display like the pagani zonda has.

I'm thinking about getting into it.

It's been done before, here's a tutorial and video http://www.instructables.com/id/Digital-speedometer-tachometer-engine-temperatu/