As the philoisopher Heraclitus knew millenia ago, "all is flux." And now an exhibit of photos documenting the changing ice sheets of earth is making the rounds. It is called Double Exposure.
It's in Roseville, California, right now. From there it goes to Pittsburgh, PA, then back out to Fresno, then to Norwich, Vermont. Here's the schedule through 2010. By then they'll need new photos to update the exhibit.