Allan Gibbard at the University of Michigan at Ann Arbor has become only the fourth philosopher to ever be elected a Fellow of the National Academy of Sciences.  Other living philosophers who are Fellows are Brian Skyrms (UC Irvine) and Patrick Suppes (Emeritus, Stanford).  Quine was, to my knowledge, the only other philosophy professor ever elected to the NAS.  Gibbard may, of course, be best-known to philosophers for his work in ethics and metaethics, but he has also done seminal work in decision theory, social choice theory, and the theory of voting.

CORRECTION:   Robin Jeshion and Brian Skyrms have e-mailed me to correct the record on philosophers elected to the NAS.  Besides those noted above, the following philosophers were also elected:  C.S. Peirce (1877), John Dewey (1910), and Ernest Nagel (1978).  So Gibbard is one of just three living philosophers in the Academy, and one of, it appears, just seven ever to be so honored.

ANOTHER:  Reader Pier Turner points out that Karl Popper (elected only in the late 1980s!) and Thomas Kuhn (if one counts him as a philosopher) were also elected to the NAS.