Back to the OP, I saw an interesting programme on whilst tellyzapping which was, I think, exploring this theory in more detail. Cut'n'pasted here from National Geographical:
Columbia University geologists William Ryan and Walter Pitman, are exploing the theory that as the Ice Age ended and glaciers melted, a wall of seawater surged from the Mediterranean into the Black Sea. During the Ice Age, Ryan and Pitman argue, the Black Sea was an isolated freshwater lake surrounded by farmland. About 12,000 years ago, toward the end of the Ice Age, Earth began growing warmer. Vast sheets of ice that sprawled over the Northern Hemisphere began to melt. Oceans and seas grew deeper as a result. About 7,000 years ago the Mediterranean Sea swelled. Seawater pushed northward, slicing through what is now Turkey. Funneled through the narrow Bosporus, the water hit the Black Sea with 200 times the force of Niagara Falls. Each day the Black Sea rose about six inches (15 centimeters), and coastal farms were flooded. Seared into the memories of terrified survivors, the tale of the flood was passed down through the generations and eventually became the Noah story.
For those living in the Mediterranean countries in Old Testament times, stories of an apocalyptic flood in that region would then easily be interpreted to be a flood of the whole (known) world, even though its impacts were not worldwide as we know it.