Tag Clouds

Using Flickr and seeing this tag cloud for the State of the Union address made me start thinking of our jobs in-terms of "clouds." If you've ever read the blog Ref Grunt you get a sense of the great deal of repetition in terms of questions that patrons ask. But it's true that you can also see the rapid speed at which things change, when certain things become popular and then drop off the map later. What if we created a tag cloud for the questions we were asked in a day, or a week, or a month? What would it look like? Would it be useful in some way?