IE: S6, E4, "Power of Three Blondes". At the end, Chris picks up the Book of Shadows. When he turns to give the sisters the spell, he was to RE-OPEN it with the bookmark!

Episode 21, season seven. In this episode they say an alchemist has the power to control the dead but not bring them back to life. However, in the season three episode "Coyote Piper," the alchemist brings both the body in the alley and Piper back to life.

Nice catch!

In episode twelve of season five, Centennial Charmed, Paige is in the Kitchen with Phoebe trying to convince her she is her sister. But watch the shot of Phoebe. A close in shot shows she's missing one of her diamond earrings. However, she has both earrings on in a far shot!