I think this is a terrific idea but wonder if it could not be taken a step (pardon the pun!) further.
With many members of the on-line network seeking support on-line because of lack of suitable support availability within their immediate area (maybe due to many factors including living in regional areas), maybe this walking challenge could be extended to include groups of on-line 'friends'.
'Virtual' groups could still compete as a team and give support to each other through messages on the on-line network system.
Just a thought on how to involve more people who may not be able to participate otherwise.
:) Deanne