Miss Parker is played by Andrea Parker, who previously was cast in the pilot of JAG as Lieutenant Pike. Doubles as The Danza, obviously. Interestingly, both are unintentional, as the character of Miss Parker was named before she was cast.
In the first-season episode "Jaraldo!", Lisa Howard plays a reporter who befriends Jarod. In Days of Our Lives, Lisa Howard played April Ramirez, a love interest to Michael T. Weiss' character Dr. Mike Horton.
Jake Lloyd appeared in about half a dozen episodes (in flashbacks, as young Angelo) before being cast as Anakin Skywalker in The Phantom Menace.
"Homefront" had a rather nasty father who has been a rather nasty person in a number of other things (including the vampire businessman who gets defenestrated in the first episode of Angel), and his ex-wife is Jan.
The two-parter "Bloodlines" stars Haley Joel Osment, in a Not-So-Small Role. Jarod must identify which one of three children is a genius. Since two of the children are unknown child actors and the last one was the lead in The Sixth Sense the year after appearing on this show, it's not hard for a post-1999 audience to guess which one it is.