MapMyFitness has Walk with Map My Walk+ (iTunes Link) for the iPhone and iPod Touch in the iTunes App Store for FREE (regularly $2.99) for a limited time.

Easily track route, pace, calories, distance, time with audio alerts and much more! Friendly, simple to use tracking tools to motivate walkers and help improve activity levels. Weight loss and social tools for those who want them. Play music! This app keeps tracking your run in the background, so you can play your iPod, run Pandora or your favorite music app simultaneously.

Great for tracking any of the following activities: running, cycling, cardio, jogging, walking, weight lifting, dog walking, cross country skiing, unicycling, downhill skiing, snowboarding, gym workouts, weight lifting, basketball, soccer, hockey, yard work, yoga, p90x, crossfit, insanity, interval training, hill runs, rock climing, hiking, mountain biking, road cycling, dance, inline skating, barbell curls, cross training, spinning, roller skating, endurance training, kayaking, horseback riding, rowing machine, elliptical, resistance, commuting, skateboarding, rollerblading, stairs, abs, sprints, golf, lap swimming, open water swimming, triathalon, track & field, group runs, treadmill, stairmaster, weight machines , trail runs, cross country running, and any outdoor activity