Sean Parker has had a hand in some of the Valley's biggest successes. His first company, Napster, took the world by storm, but didn't make Parker rich. His second, Plaxo, just sold to Comcast. And his third, Facebook — well, say no more. Except for the bit about him getting kicked out, according to Mark Zuckerberg's legal testimony, for a cocaine arrest. (Parker characterized the incident as "a misunderstanding.") That and more is covered in the 21 pages Sarah Lacy devotes to Parker in Once You're Lucky, Twice You're Good, new book about Web 2.0. The index page where Parker is listed:

"One of my roommates tells me this morning that she went to 'the craziest party ever' in Pacific Heights last night," a tipster writes in. "It involved an indoor pool, a lot of champagne, naked people, and someone in a Viking costume who said he was a Facebook founder." Ah, she must be talking about the house owned by Founders Fund partners Ken Howery and Luke Nosek, nicknamed the Grotto. And who was the Hagar the Horrible Facebook Founder? "She's trying to find out his name from other friends who were there, but said he's tall, has dirty blond hair and glasses, and is not particularly attractive." Based on that somewhat unkind description, we'd guess the Viking was Sean Parker. Shame we weren't there to remind people that Parker's not actually a founder of the social network. The party was ostensibly held to toast Microsoft's recent investment into the social network, though we've heard whispers of other reasons behind the celebration. Were you there? Snap any pics? Let us know.