Q: Is there any software that lets you type on your iPod, like on a PDA? I would like to have a virtual keyboard on the iPod screen, to be able to scroll through the alphabet with the wheel and pick letters with middle wheel button, and be able to type and save notes on the iPod.
A: Not yet.
Many people would like to see the iPod become more of a PDA, but Apple so far has not gone down that road. Allowing text input on the iPod would mean a redesign of the iPod, both in functionality and architecture.
We may see something like this in the future, but it would most likely be a totally new iPod, not an add-on to existing models.