It's our week-long duty to bring you a taste of Sundance, which is sort of like Taste of New York, except with more free swag and movies nobody is seeing.

And speaking of movies – you know, the reason Sundance exists – we're told by one Sundance insider that "none of the celebs are here promoting their movies. Last year they all attended their screenings (at least premiere screenings) and this year there is almost nobody on the A-list that is attending those."

Change, as the kids say, is in the wind. Add to the fact that, as one source tells it, "the celeb scene is not so great this year," and it's a recipe for gossip disaster. Like the disaster of Diddy's performance at the MySpace party on Saturday night.

Meanwhile, we hear that there really is no reason to abandon NYC for Park City, since as of Sunday night:

Marquee was packed with the usual Monday night Butter scene (Scott Sartiano, Dhani Jones, top celeb publicists Greg Link of Fingerprint and Matt Hein of Eastside PR) while Tao was an overcrowded party with a rough crowd. Diddy was upstairs in VIP with an oversized posse, and the smell of pot the kept floating down to the main area seemed to be coming from their corner pretty consistently. Matisyahu (rappin' reggae rabbi) got on stage for an impromptu performance and did two songs. Perez Hilton was roaming around (soooo hard to miss with that obnoxious pink hair) and was attached at the hip to Mike Satsky, the owner of stereo. CT from the real world was wearing the one outfit that he always wears on TV and looked greasier than ever.

And … then?

The after party that everyone talked about was the Heineken Light karaoke party, and people left at 4 even though it didn't end til 5 (that's a bad sign since usually everyone milks the parties until they are done).

Elsewhere, our spies file:

• DJ AM, spotted everywhere with Mandy Moore, is actually here on business: he's spinning.

• Sienna Miller did an interview session at the Delta Sky Lodge, and Diddy proceeded to show up and persuade his way inside "because he wanted to see her."

• The PM house hosted an after hours party in Deer Valley "that was so high maintenance. Super exclusive and you had to take a shuttle to get there." Guests included Diddy, Jamie Lynn Spears, Damon Dash, Pharrell, Harvey Weinstein, Nick Cannon, Sienna Miller, Josh Hartnett.

• Among the most amusing movies that are screening: Farce of the Penguins, as March of the Penguins mock that was prescreened at the house of Fingerprint PR chief Greg Link. (Makes sense, since he had a few lines in the flick.)