The second appearance of Antonio Sabato Jr. as criminal Bane Jessup. The fans liked the chemistry between Prue and Bane so he made a second appearance.
The Source is mentioned for the first time in this episode (although he was mentioned before as a "he" in Season 1).
This episode marks the first reference to a demon as "upper-level" indicating a hierarchy in the underworld. This clarification is subsequently used throughout the remainder of the series.
Throughout the episode, Piper keeps receiving signs that seem, to her, to point either to Leo or to Dan as her ideal husband. She and Phoebe, however, decide that the signs are really pointing out to them where they need to go to find Prue. This is in fact not true: all of the signs that seem to point to Dan are in fact useful for finding Prue, but some of the references to Leo have no such apparent purpose. For example, Leonardo's Boutique in Bodega Bay: Bodega Bay, which Piper initially takes to refer to Dan, is in fact meant to be taken literally, but there is no significance to the fact that the store is called Leonardo's.
Litvack is the last name of a writer & producer for the series. Steve Railsback who played Litvack is the first actor credited as a "special appearance".