Here is a link that explains the winged horse statues:
They were a part of the 2003 Centennial of the First Flight celebration on the Outer Banks as well as raising money for the wild horse fund.
Here's a link to the Wright Brothers First Flight monument in Kill Devils Hill, NC: http://www.firstflightcentennial.org/
We go to the Outer Banks pretty frequently, and the winged horse staues were a big hit in 2003. Interestingly, Pittsburgh (where I work) had a "dino-mite" outdoor exhibit of dinosaurs that year as well - to celebrate Pittsburgh's science and technology roots (the Carnegie Museum had a hand in it, as I recall). I remember the fish statues in Baltimore's Inner Harbor in 2001, and the cow statues in Chicago in 1999. For a while, these statues were a pretty popular thing. I haven't heard much about other cities doing it recently.