Apple CEO Tim Cook

The bidding hasn't closed yet, but a charity auction of a cup of coffee shared with Apple CEO Tim Cook has already attracted offers of more than $600,000 — more than 10 times its estimated value of $50,000. Cook is one of several celebrities taking part in the auction, which benefits the Robert F. Kennedy Center for Justice and Human Rights.

The coffee klatch, currently valued at $605,000, will take place at Apple's headquarters in Cupertino, Calif. And the price may rise even higher — the auction closes on Tues., May 14.