I've noticed for some time that LED lights appear to be vibrating.  However, my family and friends don't see it.  This past Christmas they kind of drove me crazy!  Has anyone else experienced this?  

 That's you seeing your own nystagmus in action; your brain can't make the natural correciton it's used to.  Especially in the dark.

 LED lights are not cotinuously lit, the electronics behind the LEDS pulses them on and off at what should be a high enough frequency so that most people think (perceive) the light as "steady".  Many albinos are able to notice the flicker of the LED light because the pulse frequency is not quite high enough for their more sensitive eyes.  Typical LED refresh frequency s 50 or 60 times a second - but this can often prove to be too low.  Bright red stop lights on a car can appear to be flickery.

Brian

 Yes, they do!  Thanks for the explanation.  

I agree with Brian. 

Another way to detect this is if you wave the light source back and fourth really fast and see multiple strings of the same light source rather than a smooth blurring of the light.  Some LED flashlights exhibit this behavior as well.

Some LED lights that use variable output to give differnt levels of brightness exhibit this behavior as well.  Example, if a light has three levels of brightness, the flickering may be noticable when dimmed down.  Many use Pulse Width Modulation (PWM) to achieve the dimming effect unless the cirucuit is fully regulated.