This isn't proof positive that Warren is pretty much tithing to himself, but it is interesting. Check out the last sentence.
http://www.philanthropyroundtable.org/content.asp?contentid=498
"Mr. Rick Warren
Author
The Purpose Driven Life
Mr. Warren is a participating dinner speaker at The Philanthropy Roundtable’s Annual Meeting on Thursday November 10, 2005 on the topic "Philanthropy and the Purpose Driven Life."
Rick Warren is an author and pastor. Time named him one of “15 World Leaders Who Mattered Most in 2004.” Dr. Warren is the founding pastor of Saddleback Church in Lake Forest, CA, one of America’s largest and best-known churches. He also founded the Purpose Driven movement, a global network of over 100,000 churches in 160 countries, and has trained over 350,000 pastors, ministers, and priests worldwide. According to Publishers Weekly, Rick’s book The Purpose Driven Life has been the bestselling book in the world for both 2003 and 2004, and is the bestselling hardback non-fiction book in American history. It has been on The New York Times bestseller list for a record 110 weeks and has been translated into over 50 languages. Rick’s previous book, The Purpose Driven Church, also an international bestseller, won the prestigious Gold Medallion Award in 1996 and was voted one of the “100 Christian Books That Changed the 20 th Century.” Forbes called it “the best book on entrepreneurship, business, and leadership.” Rick and Kay Warren give away 90 percent of the profits of the book to charitable causes, including their global P.E.A.C.E. plan, and Acts of Mercy, which serves those infected and affected by AIDS."
Certainly sounds like it...doesn't it.