Updated Image Transformation Aside from Defining Transforms in the template (http://buildwithcraft.com/docs/image-transforms) is there a way to go back and trigger an image transformation?

We've got a number of assets that have been uploaded to rackspace that need image an image transformation but the transformation was created after the images were uploaded.

Is there a way to kick this off?
I forgot we added a tool for this, too, under Settings->Tools->Clear Caches Tool->Asset Transform Index.