I love 'em for saltwater fishing too. And they're supposed to be the "politically correct" hook as they yield better results for catch-and-release fisherman.
I tried circle hooks for the first time in Kensico late in the season last year. Did catch one smallie on a circle hook using a shiner. I plan to continue the experiment this year and will report back. Please do the same if you (or anyone else) tries.
I also tried a circle hook on a wacky rig last year a couple of times. Seems like it might be an effective way of hooking a fish that takes a wacky rig. No success. . . but i have never caught a fish on a wacky rig using a regular hook either;)