The first payment of Warren Buffett's estimated $31 billion gift to the Bill & Melinda Gates Foundation went to the foundation today in the form of 500,000 Class B shares of Buffett's company, Berkshire Hathaway.

Buffett pledged to give 5 percent of the total gift each year. That's 500,000 shares down and 9,500,000 more to go. The shares are worth $3,208 each at today's closing price, for a total of $1.6 billion. Buffett requires the full value of his gift to be spent the year after it's received, starting in 2009.

Until then the money is managed through Cascade Investments, the private Kirkland firm that handles the Gateses' investments. Lest some readers get the impression that the Gates Foundation is suddenly funding media companies in its mission to save the world, Cascade's investments run the gamut from oil, silver, solid waste and ethanol to the Canadian National Railway.