It is always fun to mix some accessories into a Pilates workout, and the magic circle is one of my favorite Pilates props.
Mari Winsor (caution: The Winsor web site has automatic video/audio) has a 20 Minute Circle Workout DVD. This workout is short and to the point. Adding leg squeezes to ab work just seems to make the abs work more deeply. Plus it is nice to work lazy inner thighs! This DVD contains exercises that work all body parts, with an emphasis on the abs; it is Pilates after all.
In this DVD there are options for different levels of students. One of the three demonstrators does beginner versions of all the exercises. These variations would also work if you are dealing with a neck injury. One odd thing about the DVD is that the three demonstrators are all so well behaved, polished and choreographed there is an air of "finishing school" about the workout.
The DVD also includes a basic aerobic workout with Pilates lingo added into the mix. The aerobics or "Accelerated Fat Burning Workout" is fine, but I'll stick to Jamie King dance routines – thank you very much.