Stargate Atlantis actor David Hewlett (“Rodney McKay”) — and his dog, Mars — goes incognito as Ronon Dex in his latest contribution to YouTube. It’s all to promote MGM’s new video contest, where fans can submit their best original, Atlantis-related videos for a chance to win an Apple Macbook laptop computer and a live video chat with Hewlett.

Other prizes include an autographed costume from the set of Stargate Atlantis, an autographed script, autographed DVD set, and more.

Visit www.youtube.com/group/mckaycontest for complete contest details and to post your video. The deadline is July 30, so get to work!

MGM is also sponsoring weekly trivia contests at its official site, where fans can win an autographed copy of Stargate Atlantis: The Complete Second Season on DVD. The first round is set to begin today!

Hewlett also announced that his independent film “A Dog’s Breakfast” will be available on DVD this September.

New episodes of Stargate SG-1 and Stargate Atlantis are now airing Fridays at 8 p.m. and 9 p.m. Eastern/Pacific on SCI FI Channel in the U.S.