Seat tube sleeve cut to mirror the fork crown and bring the bike together.
I have John N. to thank/blame for this. The spade headtube badge on his bike ( http://www.bikeforums.net/showthread.php?t=509497&highlight=Matthews) makes everybody want a version of their own. I don't blame them, it is a nice way to further personalize your dream bike. So much so that I'm thinking of making this standard for all my frames.
This one is a "om" a buddist symbol for bliss/enlightenment/a comatose state, I don't know for sure, but Cara wanted it, so there it is.