According to Nonprofitist.org's post, How Many International Nonprofits Can You Count? there are 1.4 million nonprofits in the United States. Charity Governance reports that, "For the period from October 1, 2006 through September 30, 2007 (fiscal year 2007), the IRS received 85,771 applications for recognition of Section 501(c)(3) status."
That's a lot of nonprofits, many that are doing similar work and competing for funding from foundations and individual donors.
To celebrate, and learn about best practices in nonprofit collaborations, the Lodestar Foundation has launched a $250,000 Collaboration Prize:
How will you spend your economic stimulus check?