Amanda Tapping and Christopher Heyerdahl appear together in this episode. They would both go on to star together in TV's Sanctuary (2008). It is also interesting that Heyerdahl plays two characters in both this series and in Sanctuary.
In the beginning of the episode in Sam's office you can see a collection of photos behind her. They are of various SG-1 characters. You can see Cassandra, Daniel, Teal'c, and Jacob. Other episodes reveal a photo of Jack in her office also.