Emily, Leslie Sansone leads a walking "class". There are 4 basic steps: walking or marching, kicking, side steps and knee lifts. Different videos incorporate other steps as well. Some videos use "boosters" - stretchie bands, weights, a walk belt, jogging. Arm movements are used in all of the videos to give you a "total body experience".
Each series is set to a different pace. For instance the pace ranges from 3-5 miles per hour depending upon the video.
Why I like them so well (I sold my treadmill because it was boring - even using the tv, books, music) is because you are led. I don't have to think. It is already scripted and I can just follow. Quitting early isn't an option. There is enough change of movement and change of pace to keep me from getting bored. The other participants on the video have a good time and it shows. I have found videos (walking and dance series) to be an important part of my exercise regimen. I like to walk outside as weather permits, but I actually get a better workout using the WATP series. And - I can do it any time

collagevideo.com has clips of all of their workout dvds. You can take a peek and see if you think it would work for you!
HTH