Facebook plans to hold its long-rumored, long-wished-for IPO the third week of May, sources tell Kara Swisher of All Things Digital. That would mean documents would have to be filed in a matter of weeks, since the SEC generally takes three to four months to evaluate them. Swisher is pretty confident in the scoop—"I called 143 people on this one," she brags—but warns that IPO planning can always "change, in a New York minute, to another month." (More Facebook stories.)