Here is a list of interesting services that use sensors in mobile phones in some new or creative way. These are not necessarily related to physical activity, but to health tracking in some way. They might ultimately benefit from new services that could be provided using Wocket-like devices and activity recognition.
    Map your activities and share with friends on mobile phone using GPS.
    Advice and feedback on weight managment through mobile phones.
    Personalized nutritional information based on photos of what someone eats.
    Inspirational message delivery using mobile text messaging.
  • Tweet what you eat!
    Using twitter to capture dietary intake information.
  • Firstbeat Technologies
    Heart rate signal processing to measure mental, physiological stress and training effect.
  • Runkeeper iPhone app
    An app built for the 3G iPhone that uses the built-in GPS to track outdoor fitness activities including duration, distance, pace, speed, and path travelled on a map.
  • iPhone/iPod digital fitness companion
    Concept system that includes an iTunes-like software application, hardware-based heart rate and physiological sensors, a rewards tracker, and a component to facilitate synchronous group activities.