On your Fitbit app you can add your friends who also have Fitbits to monitor their steps. Mostly I've just used the "taunt" feature, which is like a Facebook "poke" but with a better name.
I only have one friend who regularly uses a Fitbit, Ariane. After I added Ariane to my Fitbit friends, I peeked at her average. Ariane averaged 12,000 steps per day.