This introduces the Tollan, a people that would make further appearances on the series.
Opening scene. "This is like Pompeii, everyone died of suffocation before the lava started to flow." First, there was minimal lava associated with the 79 AD Mt. Vesuvius eruption, and none got anywhere near Pompeii. Second, while folks used to believe the people suffocated, that explanation never explained the live action postures of the majority of the bodies. It is now generally accepted that the fourth of the eruption's six pyroclastic surges killed the people. A pyroclastic cloud can easily reach temperatures over 500°F and move downslope at several hundreds of miles an hour. The citizens of Pompeii probably died instantly from heat shock.
First appearance of the SGC UAV (Unmanned Aerial Vehicle). It is used primarily for recon but, in later seasons, can be used to help identify and mark targets for artillery.