Said in a flat, childlike voice, usually meaning boredom or whomever you're talking to isn't worthy of your attention. Said by Willows Doppleganger (Buffy the Vampire slayer)
VampWillow: **tilts head** Bored now...
Annoyed girl talking to stupid boy: Bored now...
Showing you have lost all interest in a certain subject, to the extent that you are happy to kill it. Willow Rosenberg's evil, vampire, Doppelganger and Dark Willow both used this line in Buffy the Vampire Slayer.
It has a sinister quality to it, almost exerting one's superiority over another in a certain situation, showing how meaningless the subject is to the person saying it.
Warren Meers: "Oh, and when you get caught... you'll lose them too. Your friends. You don't want that. I know you're in pain, but..."
Willow Rosenberg: "Bored now."