Could you post a screenshot of something you have in mind?
The mockup by Aaron is a good example.
Here's one of Stephen Few's mock ups which I lifted from Andy Kriebl's blog at VizWiz - Data Visualization Done Right
I really appreciate the way the circles only appear on those measures that need immediate attention. They grab the viewers attention to draw their attention where action is required. I'm surprised there isn't a native way to do this within Tableau (baring a clear image hack).