Does anyone know what official channels we should be using for suggesting improvements for the Droid?

The Droid is an amazing device, and I can live with most of the warts as they are worked out. But the email client is currently a real showstopper. As I'm sure most of you have discovered, IMAP functionality is sorely lacking, with no delete on server capability. Add the inability to move/copy msgs between folders and no signatures, and it's a sophomore effort at best.