Venture investment in Web 2.0 companies rose at a healthy clip in 2007, as total investment, per-round sizes and valuations all saw gains, according to full-year statistics from Dow Jones Venture Source.

Total investment in venture-backed startups rose to $1.34 billion from $716 million in 2006, according to the figures, released on the eve of the data firm's Web ventures conference.

Much of that gain was powered by Facebook, which raised a total of $300 million, including $240 million from Microsoft at a valuation of $15 billion.

Ning, with a round of $44 million, Metaweb, at $42 million, Zillow and Metacafe, at $30 million each, rounded out the Top 5 deal sizes.  

The average investment round climbed 20%, to $5 million from $4 million, while pre-money valuations leaped by 66% to $10 million from $6 million.

While much of that was driven by the huge Facebook investments, it shows that VCs were willing to accept smaller equity stakes, on a percent basis, for their money -- at least last year.

Whether that trend holds up this year, with the U.S. economy and stock markets melting down, remains to be seen.