Alison: about the "grapevine" movements you're seeing runners/walkers do - are you referring to the drills? These are sideways stepping exercise to develop balance, coordination and stepping technique (so you aren't dragging your feet or stumbling over them). It looks a little like dancing and you're likely to see runners doing drills in warmups prior to an event, or as part of our track workouts.
Kristin: as a runner, you can certainly incorporate drills, calisthenics, Pilates and yoga as part of your core and cross-training. I know I need to focus more on these types of strength training exercises for better injury prevention (my recent knee injury during my last marathon a case in point, yikes!).