I was channel-surfing and as I passed the fifth channel to be airing some variety of Stargate (I mean, it's ALWAYS ON!), I saw the Liandra's Covert Ops man, Malcolm Bridges on Stargate: Atlantis. IMDB says he has appeared in 3 out of 5 episodes as Sgt. Bates. I guess that makes him a regular (with back end credit), unless some lava monster kills him in episode 6.