A couple of weeks ago I had a very productive day on a stony beach, despite cold winds, salt spray and occasional rain. The K10D and the DA* lens performed flawlessly, and I spent hours playing with the surf over the rocks. I took many abstract shots like the below, but they need a lot of time to grow on me before I can decide which ones to go on with. This is one I like a lot at the moment.
Pentax K10D, DA* 16-50/2.8
f/13, 1/15s at ISO 100