One of the things that makes the iPod touch different from the iPhone is that you don't necessarily use the iPod every day. In fact, I often go a week or more without using it. And when I finally turn it on and load the Mail app, it can download 200 or more emails -- all of which I have to tag one at a time in order to delete them. This is unbelievably time consuming. It would be so convenient to have a Tag All selection, from which I could manually untag the emails I want to keep.
20" Intel iMac with 1.5 GB RAM ..., Mac OS X (10.5.3), iBook 14 incher, little orange Shuffle, iPod touch