Disproving the old adage, “you can never go home again,” Tori Spelling guest stars on tonight’s “90210,” airing on the CW.  It’s been years since “90210″ fans have seen Donna Martin, who will reconnect with lifelong friend Kelly Taylor (Jennie Garth) on the episode. Spelling talks about the enduring influence of the original series, and how the show has become a multi-generational habit! (CLICK BELOW THE VIDEO TO HEAR TORI SPELLING)