[O] All TODOs are equal, but some are more equal than others...

[Marcin Borkowski]

Dear collective Org-mind,

I really want to use the global todo list, but it's not that useful when
I have almost 100 entries on it.  I'm looking for ways to reduce this
number.

The problem is, I have two kinds of TODO items.  Some of them are things
I should do ASAP (but not on a particular date, so they are not
timestamped), and some of them are just ongoing projects, or
articles/blog posts I want to write some day (but not "some indefinite
day in the next 30 days", rather "some day within the next two months or
so").

Do any of you have a good way to differentiate between the two?
I already have

(setq org-agenda-todo-ignore-with-date 'all)
(setq org-agenda-todo-ignore-timestamp 'all)
(setq org-agenda-todo-list-sublevels nil)

in my init.el; maybe marking the parents of the entries I'd prefer to
filter out DONE is some idea?  (I don't like it, though.)  Maybe tags or
properties?

Any hints?

TIA,

-- 
Marcin Borkowski
http://octd.wmi.amu.edu.pl/en/Marcin_Borkowski
Faculty of Mathematics and Computer Science
Adam Mickiewicz University