David Hewlett battles the Yeren!
There are at least seven photos of Stargate Atlantis' David Hewlett working as director (and clowning around) at this Flickr page - http://www.flickr.com/photos/craige17/
This is one of the goofier ones posted.
Thanks to simboo for the tip! And for 'Gler' for posting them! No copyright infringement meant or intended by reposting the picture.