Dave O and I have been talking about measuring the SRC guoy phase by dithering optics in teh corner station and looking at the motion of the beam at the AS port.  This should allow us to work out the ray transfer matrix for the SRC cavity.  I misaligned PRM, and ITMX, and misaligned the SRM slightly so that two beams could be seen on the AS camera:  a straight shot beam through the SRM and a beam that had made one round trip of SRY.  I put exictations on the optic align stage of BS and PR3 auapensions and tracked the beam motion.  I now need to do some further analysis on this.  All optics have been returned to their nominal positions.