MyYearbook, a social network for teens turned off by the old people thronging Facebook and MySpace, has raised an additional $13 million in venture capital. The social-network startup wooed by Barry Diller's IAC last year, but a deal never happened. The site claims to be the third biggest social network in the U.S.

Managed-hosting service Rackspace has filed with the New York Stock Exchange to raise $400 million in an initial public offering. Investors Norwest Venture Partners, Sequoia Capital and company chairman Graham Weston stand to profit from the exit. Rackspace reported $18 million in 2007 profits on $362 million revenues. We called the IPO in January, but we're not sold on its merits.