I went to Wikipedia in order to be clear about what a tall tale is, and I have adapted some of their text:
A tall tale is a story with unbelievable elements, related as if it were true and factual. Some such stories are exaggerations of actual events, fish stories ('the fish that got away') such as, "that fish was so big, why I tell ya', it nearly sank the boat when I pulled it in!"
The tall tale is a fundamental element of American folk literature. The tall tale's origins are seen in the bragging contests that often occurred when the rough men of the American frontier gathered. The tales of legendary figures of the Old West owe much to the style of tall tales.
Sarah Palin is -- or would have you believe that she is -- one of the rough women of the Alaskan frontier, so it shouldn't be too difficult to find at least one instance of an exaggeration -- a brag? a tall tale? -- by Sarah Palin.