Kris--
The most notable use of Dry Hazards has to be at Oakmont. They appear on a number of holes, such as 2, 5, 9 (can catch a quick hook of 1), 11, 12, and I think there is at least one more. The thing about the dry hazards at Oakmont are there close proximity to the fairways, particularly in the driving zone on 9 and the layup zone on 12. Ernie Els hit his drive in the final round of the 1994 Open in the ditch on 9 and was fortunate to make 5. The thing is that you really have to respect them from a playing perspective because you have real problems if you go into one. The ditch on 12 is quite deep, as a matter of fact, Oakmont has placed ball retrievers along the edge of the one on 12 because of it's depth.
The one thing that I'm not sure about is whether the ditches were solely meant to be penal (the fairway stops short of them on 5 and 11) or were a major component to the drainage of the course. That's the one thing that the Fownes were really ahead of their time on, they can get water off the that course quickly, one look at those greens during a heavy rainstorm is a great illustration.