My son who is in NC on the outer.banks saw this bush. It is about 20 feet...
Those are Oleander (Nerium oleander), which are beautiful. They are native to Southern Asia and the Mediterranean and so grow well in our southern states, but not well here. They are only hardy through about zone 8. They are however available from nurseries in our area, sometimes listed as 'patio tropicals' for use during our growing season as accent plants, usually in pots, similar to how we grow hibiscus, mandevilla and gardenias.
Here is a page from North Carolina Extension about them. They are often grown on the coast there due to their high tolerance for wind and salt: http://www.clemson.edu/extension/hgic/plants/landscape/shrubs/hgic1079.html
One more thing: Beware! All parts of this plant are toxic. Take care if grown in homes with curious children or animals.
Thanks for the response and additional information. Really great to have this resource. Can not ever remember seeing an Oleander bush.