Your thoughts on iPhone Todo Mgmt. done right

[mathias]

We would like to receive your input on what you think the key
ingredients to "the best iPhone Todo Mgmt. application" would have to
be. Of course we do have an opinion on this, however, your collective
experience is not something we want to ignore.
To keep the discussion on track, these are the points to keep in mind:

1. Even though the goal of becoming "the best iPhone Todo Mgmt. app"
does involve a comparison to other apps we are not trying to do the
same (just better) or something necessarily different (an unoccupied
niche). The goal is simply: Doing things right. Whether others are
doing parts of it already or no one is doing it so far is not
important. The single thing to focus on is: What do the users need?
(Of course, if you think there is no need for listo since someone else
is already doing it right, we would like to hear your arguments too!)

2. When talking about "the user" we need to try to envision him or her
as the "80% of everybody" user. All features only relevant to specific
user groups making up less than 20% should not be part of this
discussion. Of course this is a blurry line, not only because, in this
case, "everybody" already denotes the group of people already "owning
an iPhone and generally interested in using it for aiding their time/
todo mgmt.".

3. We see the iPhone app not as something stand-alone, but rather
something embedded into a network of online/web services, desktop apps
on various platforms, etc.. That's why we should not limit ourselves
to sole discussion of device specific solutions.

To get things started, this is an extract of our current thinking:
a) The iPhone app is simply another UI onto the users current "todo-
space", which exists in a device independent, virtual location. All
UIs (desktop, phone, web) have a view onto the this same "todo-space",
which is updated in real-time.
b) The iPhone app should be optimized to a reading/writing ratio of
about 2/3 vs. 1/3, i.e. the majority of user interactions will be
consumption of todos, not production.
c) Even though only one third of all user actions will be todo writing
it should be possible to enter a new todo in the absolute minimum time
possible, i.e. with the minimal number of "clicks".

Features:
A) "Drill-down" folder level logic, similar to the iPhone Mail app.
B) Quick and easy filtering of tasks for the ones due today and the
ones resulting from a full-text search.
C) Number of due tasks visible in the dash board.
D) Make reminders really remind. Given the current technical
restrictions we'll try everything possible: Server-triggered reminders
(with coming firmwares), mail, SMS, maybe even call-based reminders.

So much for the current plans.

All thoughts are welcome.

Cheers,
Mathias