[open-data-day] Hashtag

[Données ouvertes 101]

I've already been using #ODHD13, and even using #ODHD13Mtl for messages
that would not really be pertinent for international.

Our wiki, graphics, posters show #ODHD13.

Would be nice next year to talk about the hashtag kind of beginning of
January ;-)

Pascal
Montreal2013