World Building Saturday

Today we're building worlds!  I have three (at least) I want to do... is that overly ambitious?  One already established, one semi, one not at all.
Do you ever look out from a height across the land and get this itch, this electric feeling like you want to populate the land?  Draw in all the infrastructure and people and challenges?
I've got a new story in the works (understatement of the week).  I'm thinking of doing the 30 day world-building challenge to give the story a solid setting.  Solid settings, liquid settings, gaseous settings...
Tune in again later, or join in the challenge!