How to send Apple suggestions for future iPhone features?

Whats up!

New to iPhone forum, not new to forums. I've had my iPhone for 6 months now and love it. There are a few things I was hoping the 3.1 upgrade would include but appears it doesnt.

1. Ability to change sound for email notification.
2. Ability to include in search function to search through pictures.

Does anyone know if these are going to be included in future upgrades? If not how can I send a suggestion to Apple so they at least know its something that would be appreciated.

Thanks