There isn't way to have the auto-updated when new data comes in is there? I'm using version 7.017, thanks
Still the top rated Idea on the forum: http://community.tableau.com/ideas/1178
Might want to look at Jonathan's blog post, but I'm not sure if being on version 7 affects this:
Creating a Dynamic “Parameter” with a Tableau Data Blend | Drawing with Numbers
Retrieving data ...