Trivia: When Daniel tells the others that he believes there is an entire network of Stargates instead of just two, he and Carter figure out that they have to adjust for stellar drift in calculating the new gate positions. She mentions that they should be able to 'MacGyver' something together. This is of course a nod to Richard Dean Anderson, who played MacGyver.
Trivia: In the scene where Samantha Carter is about to release an EM pulse in the room in an effort to discontinue Urgo's annoying appearances, Urgo is protesting his "demise" and trying to prove he won't bother anyone anymore. He says, "What about this?" and changes into a younger man in military uniform. "Can you resist this?" he then asks before he switches back to his familiar form. The actor playing Urgo, Dom Deluise, is actually replaced by his son, one of the directors of Stargate SG-1, for this switch.
Trivia: In classic Star Trek, Kirk and Co. travel to an alternate universe where Spock and the rest are evil and Spock has a goatee. In this episode, Daniel travels to an alternate universe where Teal'c is evil and has a goatee. The name of the classic Trek episode? "Mirror Mirror". How does Daniel get to the alternate universe? Through a mirror.
Trivia: Near the end, right after they come out of the stargate to the Alien planet, there are lots of artifacts laying around. Look to your right, and you'll see what looks like a space pod. It's the same one Rita Repulsa came out of in the first season of Mighty Morphin' Power Rangers.
Trivia: In the final episode, "Unending," just after Thor beams aboard, Vala asks Daniel how he can always tell one Asgard from another, given that they all look the same. He replies, 'it's the voice'. This is a subtle nod to the fact that Michael Shanks, who plays Daniel on the show, also provides the voice for the Asgard characters, Thor, Aegir, and Penegal.
Trivia: Originally the show was to finish around the time Apophis was finally killed (which we saw in season 5 episode 1) Later on the show was supposed to finish at end of season 7 with a feature film but ratings made the show continue on from season 7. After season 10 there were two feature films. Any other planned films to do with SG1 where cancelled due to the show's production company running out of money. One of the cancelled feature films was about Jack O'Neill and introducing the Stargate to the public.