From Marly Falcon, Knight Foundation contributing blogger:

The Giving USA Foundation, which publishes data and trends about charitable giving, released its annual report on philanthropy for 2008. The report shows that in 2008, contributions of $307.65 billion were given. Only 14 percent of the contributions were from foundations, which totaled to $41.21 billion.

See the chart below for the complete breakdown of charitable giving in the U.S. during 2008.

The preceding graph is from the GivingUSA Foundation's 2009 annual report: Giving USA 2009 The Annual Report for Philanthropy for year 2008, released this year.