An Argiope Spider
Look at the size of this spider, it must of been about four inches across. It had no idea what it was, so I had a look on the net-
From a spider site-
"The largest orb weaver in our gardens is the black and yellow argiope (Argiope aurantia). Actually, only the female is large, the males being much smaller by comparison. Although big enough to deliver a bite, these spiders are not poisonous or aggressive. The black and yellow argiope is also called banana spider, yellow garden spider, zipper spider, golden orb weaver and writing spider. There are a number of other species in the genus Argiope, but most that occur in the U.S. are restricted to tropical climates. A related species inhabits gardens in Europe. Because they make such big webs and are brightly colored, it is impossible for a resident argiope to remain unnoticed in the garden or, as they sometimes look for sheltered areas, on the side of a house"