Keep Circulating the Tapes: Season one got a DVD release and is even popular enough that 7 episodes of it are on PlayStation Network. The other 4 seasons? Not so much. iTunes only has 35 episodes, all from the first four seasons.
Unintentional Period Piece: Good God. The intro alone could easily date the series to the 90s and that isn't even getting into the the characters clothes, the style of the house, Clarissa's old 90-something era computer, and her taste in music. She's mentioned wanting to see Pearl Jam and Nirvana live, and has stated to having a slight crush on John Linnell.
In 1995, a spin-off called Clarissa Now was pitched to CBS. It would have shown Clarissa as a college student in New York, working as an intern for a newspaper.
Interestingly, that was almost the exact same career path that Melissa Joan Hart's next character, Sabrina, did follow after high school. This has led to more than a few people joking that they didn't know it was two separate shows, and just assumed that Clarissa woke up and discovered she was a witch.