Surviving in Space Without a Spacesuit

Geoffrey writes "The recent movie Sunshine features a scene (echoing the famous scene in 2001: a Space Odyssey) in which two astronauts have to cross from one ship to another without spacesuits. But, can you survive in space without a spacesuit? Morgan Smith, writing in Slate, asks whether this is realistic, and concludes: "Yes, for a very short time.""