The focus racking function and the fact that some lenses are able to report focus distance, made me wonder if it's possible to make focus presets that would not vanish even if the camera was turned off and battery removed - that is, saved on the card. This could be useful in some cases, for example if you're planning a bulb exposure in very dark where it's difficult to focus by normal means, or simply want to save an often used focus distance.
As an example, I might want to create a preset of, say, a certain 28mm lens focused to infinity at maximum aperture opening, and save this preset for later use, with a custom description of the settings involved.
I can think of at least two alternative ways to achieve this (there is probably room for improvement):
The user first turns the focus ring to either extreme end, and then focuses the lens to the desired distance, using the follow focus function controlled by arrow keys. The camera saves the number of steps required, and uses that information to restore the desired focus.
The user simply focuses the lens to the desired distance by whatever means, and then creates a note using the "reported focus distance" function in Focus menu. However, I think the number of values reported are currently too few for very accurate focusing. For example, 500D's kit lens (18-55mm IS) reports only 14 distinct values.
What are your thoughts, does this sound feasible? Not that it's a matter of top priority, but something that you might want to think about after the more urgent issues.