A Dow Jones VentureSource report released Tuesday indicates that Web 2.0 investment may be peaking in the United States despite an 88 percent increase in money investment in 2007 over 2006. Even though venture capitalists threw a record $1.34 billion into 178 Web 2.0-related deals in 2007, the Dow Jones data reveals that the number of deals has finally slowed after several years of rip-roaring activity.