According to the blog post (http://blog.trello.com/launch/ http://blog.trello.com/launch/), "It’s free. (We might charge something for premium features in the f

According to the blog post (http://blog.trello.com/launch/ http://blog.trello.com/launch/), "It’s free. (We might charge something for premium features in the future). You can make one board or 100."