2010-07-29 - Eugene, OR - Sphere

I went outside to have a cigarette and saw a object larger than a star moving erratically, back and forth then hovering, then moving across the sky at a very high rate of speed. Object was white changing to red then green then back to white. Object was seen moving and then hovering for a few seconds. It was not any type of aircraft and it made no sound. I thought it looked like a giant laser pointer in the sky. When it went across the sky, it went from the southern most horizon to the northern horizon in no more than 2 seconds. I have never seen anything like this before. After about 10 seconds object came out of the northern horizon back to its original position, all the while changing colors, again object made no sound. Object then rose up to zenith above my head, pulsated colors for a few seconds and then disappeared. The object was there one second and gone the next and did not return.