Unhappy with your current sports watch? Wish it had additional functions, or interfaced with some other electronic gear you have with you on your runs? Want to get your hands messy programming the sucker yourself? Then check out the eZ430-Chronos:
It is equipped with sensors for measurement and motion-based control and can serve as a central hub for nearby wireless sensors so that users have remote access to real-time data from devices such as pedometers and heart rate monitors. Additionally, Chronos includes a USB-RF access point for wireless set-up and PC connectivity, as well as multiple production-ready open source projects to foster easy evaluation, design and community collaboration.
Sadly it doesn’t have a GPS receiver, but theoretically you could tie in a separate GPS wirelessly. If you’ve got the programming chops for it, that is. Definitely a toy for the runner who spends more time (and money) on gear, preparation, planning, tweaking, etc. than on running.