There have been a few posts recently on portable rock art. I actually stumbled across this on Arran a few years back, didn't have a camera but tucked the stone to the back of my mind. On holiday there a few weeks back, I was staying just s few hundred yards from the stone and hauled it out for a photo session on our cottage lawn. Only three pics came out (it was very sunny). Any thoughts/ opinions on this rock would be appreciated.

http://www.flickr.com/photos/47595583@N06/sets/72157635037625551/

You can click and view these photos "large size". Peck marks, lichen and dark patina in the grooves are quite clear.
Any thoughts appreciated.