This round of speculation brought to you, yet again, by The Wall Street Journal, which this afternoon quotes "people familiar with the matter" describing a potential Microsoft investment of $300 million to $500 million in social networking site Facebook. It adds that those figures would buy Microsoft 5 percent of the company, putting Facebook's value at $6 to $10 billion, and that Google is another potential investor in the company.

The story also includes the obligatory no comments from Microsoft and Facebook. The article cautions that these people call any deal "still preliminary and Facebook could wind up not taking an investment from either Microsoft or Google."

Microsoft and Facebook hooked up on an advertising deal earlier that Microsoft was most proud of. And, as the Journal reported almost exactly a year ago, Facebook has done the deal dance with the tech biggies before. That story included this memorable anecdote about Facebook founder and CEO Mark Zuckerberg being something of a late riser during negotiations with Redmond about a potential acquisition:

"During one series of talks with Microsoft, Facebook executives told their Microsoft peers they couldn't do an 8 a.m. conference call because the company's 22-year-old founder and chief executive, Harvard dropout Mark Zuckerberg, wouldn't be awake, says a person familiar with the talks. Microsoft executives were incredulous."

For more background, see Microsoft's own page on the digital advertising deal it landed with Facebook last August.