I really like the Yahoo! Mail app, because now (finally!) I can read emails in any folder at the same easy-to-read full size font like the iPhone's native Inbox has. But where's the checkboxes like in the regular Yahoo! Mail? Unless it's tucked away somewhere I haven't seen, there doesn't seem to be a way to select emails using checkboxes (Delete, Spam etc.) in the Yahoo! Mail app.
UPDATE 7/30/09
Yahoo! has added the boxes, yay. However, I don't see a 'Check All' option to be able to do bulk moves like in the regular Yahoo! Mail. Hopefully, they'll add that next.