I'm looking forward to the score board feature being available for small groups so I can run a mini fitness challenge against my friends and family.

A fitness point roughly translates into a calorie, while an activity point allows you to compare your exercise to anyone else on the site. Now here's where it get's clever - you can signup on various scoreboards on the site and compete against other users!
Even better there's a nice whistling line you're going to find it hard to forget, and not to imitate!