I also love the majority of the carved subjects; usually Greek or Roman mythology... which is actually where a lot of cameos originally derived from. Here are some of my Roman soldier cameos! Some are also called intaglios, where the image is literally carved into the material, so that the background is raised higher.
Instead of just collecting the cabs (which I have been designing jewellery around and hopefully my father can make it all up for me one day!)...I've also been looking at other things that have cameos, and my most recent purchase has been this little trinket box with Athena at the front. (Well, I like to think it's Athena!)