In Email, after you use the "edit" button, the Trash folder has a button with which all Emails can be deleted with one press. I'd be curious what others think of having this button in all Email folders? The reason is this: When I open the inbox, all Email that is stored on the server of my ISP is put onto the iPhone. As a result, I always get few thousand Emails in the inbox, and it sure would be nice to get them all off of the phone quickly and easily.
I like this idea. I have lots of messages on my phone and it would be cool if there were a way to not have them all stored locally. Sure, I want them on the server. But just not on my phone, if that makes sense.