facebook.jpgFacebook, the Palo Alto company that has all but sewn up the U.S college market with its online social networking offering, today announced it is going after U.S. high schools.

This is what he had hinted at in our post last week.

The high school offering is a separate product: High school students get to fill out profiles and connect with other students at their own school or friends at other schools. But it is not integrated into the college product.

Call it Facebook’s end-of-summer surprise. They’ve been working on it feverishly. In fact, we had a hard time reaching CEO Mark Zuckerberg for our story last week, because he was in “lock-down” mode, basically where he had a sign on the door saying no one can bother him. Clearly, this is a move that treads more on MySpace‘s turf. “They have a lot of high school users,” Zuckerberg acknowledged in our interview.

Btw, the NYT has a good story that includes a look at Facebook, suggesting is part of a group of companies where the valuations, or the value the venture capitalists agree upon when they invest in the companies, are a bit bubbly.

Among venture capitalists it’s a poorly kept secret that Facebook’s valuation came in just shy of $100 million. Assuming that’s true (Mr. Breyer declined to say), Accel paid a little more than $12 million for roughly a 15 percent share. Which is a very steep price for a company that even Mr. Breyer acknowledges is a risky venture.

However, we’ve talked with others who think the valuation is reasonable for the sort of traction Facebook has. The NYT notes that about a dozen firms competed to invest in Facebook. We talked with Zuckerberg about why he turned down an investment from Don Graham, of the Washington Post — who had become a friend of Zuckerbergs. Zuckerberg said he’d been committed to taking money from the Post, but that Breyer made a slightly better offer. Zuckerberg was torn, but Graham counseled him to take the money from Accel.