appointment implement variable warning time

[Ivan Kanis <expire-by-2010-01-02@kanis.fr>]

Hi,

I use appointment with org. I find that a global time delay for each
appointments is inconvenient. For example I need to be warned an hour
before an appointment downtown and only 5 minutes for a meeting at
work. I have hacked appt.el to keep track of a delay for each
appointment. The function appt-add is compatible with the old appt.

It should be applied after the feature freeze of emacs. You can download
the new version from my website http://kanis.fr/blog-emacs.html

Now I would like to hook this change this with org. I don't think it
would be a good idea to extend the timestamp as it's already pretty
complex. How could I add the number of minute in an entry in a way
that's not obtrusive?

Thanks for your ideas.
-- 
Ivan Kanis
http://kanis.fr

Parting is all we know of heaven, And all we need of hell.
    -- Emily Dickinson