Riding on the back of the Country Walking 1000 mile challenge,
Viewranger are doing something similar, with a choice of 250, 500, 1000 and 1500 mile challenges.
They admit they were inspired by Country Walking's Walk 1000 miles after reading someone's blog who used Viewranger to log and keep track of their distances.
All you need to do is sign up to your chosen challenge, track record every walk you do using VR and the app/site does the rest, including adding you to a leaderboard.
Might be of interest for anyone who wants a goal for 2017 but feels 1000 miles is beyond them
... And no, you can't take 12 devices with you and track 1 walk on them for the mileage to be multiplied by 12