GreasyJack:
Again, not a single point, but there is a relatively small area in Wyoming that is drained by at least 4 distinct watersheds. In the area south of the Grand Tetons, at various points water flows to the Atlantic and the Pacific, but also into the Great Salt Lake and the Wyoming Basin, which are both internally-drained (i.e. have no outlets).
This region also has the very bizarre Two Ocean Creek, which is a single creek that flows into a swamp on the continental divide which is in turn drained by two creeks, each of which flow to a separate ocean.
Been there, and deliberately pee’d into the Atlantic and Pacific Oceans at the same time. That was really un-called for, but you do thing when you’re young.