In the youth culture of social networks, the worst thing to be is the old guy. Even News Corp. CEO Rupert Murdoch, after shelling out $580 million for MySpace, has tired of the website. And the Facebook frenzy could fade equally fast, if more people follow Jason Calacanis's lead and declare Facebook fatigue. That's why Plaxo has a shot — if a shaky one — at transforming itself from spammy address-book manager to the hot new thing, when it relaunches as a networking site on Monday.

Plaxo's motivations, of course, are purely mercenary. Everyone wants a piece of Facebook's magical billions. Where Facebook is weak, of course, are its not-so-private privacy settings. Your choice, when adding someone as a facebok "friend," is to offer them either an insulting (and easy to spot) "limited profile," or open the kimono, drunken party shots and all.

Plaxo, by contrast, offers more fine-tuned controls in its new Pulse social network. And, most importantly, for self-important self-promoters like podcaster Robert Scoble, it offers total control over how to spam your fans. The premise: Plaxo users will be able to designate contacts as dysfunctional family members, insincere friends, smarmy coworkers, casual acquaintances, or desperate hangers-on, and treat them accordingly — never leaving them the wiser as to their classification. Your friends will never know how limited you think they are.

If the goal is to boost its buzz, and with it the company's valuation, Plaxo's social networking bid certainly makes sense. The company's software already actively updates address books, but that's about as exciting a business as LinkedIn. The new Plaxo aims to be the Web's social butterfly. But before it emerges from the chrysalis, let's all stop and ask ourselves: Can we face the propspect of having another social network to update without going mad? At some point the old and familiar outdraws the shiny and new.