The discussion of a) overly-long checklists that don't get used and,
on the other hand, b) the need for checklists reminds me of a
discussion with a power instructor (instrument), who made a
distinction I hadn't encountered before, but it made sense. He
distinguished between a written procedure, a written checklist and an
oral checklist. Here's the idea:

Written procedu a written sequence of steps to take.
Written checklist: a written list of things to check.
Oral checklist: a memorized checklist. Should be very short, and
memorable, used only for a few last-minute and "death/destruction"
items.

A written procedure may be quite long and can be detailed. It may
contain some lower-importance items. It is used for setting up the
aircraft and should be used when there is time for it. Sitting next
in line for takeoff on the runway, barreling down final approach, or
right after a rope break - not good times for a written procedure.

A written checklist may also be quite long. Often it's the same as
the procedure list, but it should contain only short reminders of only
the important items: its purpose is to confirm that the aircraft is
already properly set up. Written checklists should also be used when
there is time for them. They provide a double-check; their
disadvantage is that they rarely identify anything wrong, so human
nature makes it easy to miss something. It's mostly for that reason
that a checklist should be as short as possible and should stick to
truly important items: no zipper-checks.

In 2-pilot operations, the written procedure and checklist can be
combined in a single document, but the functions are separated by the
challenge-response between the two pilots. For single pilot
operation, this instructor did NOT like the approach of
read-it-do-it-confirm-it all in one pass. It's too easy to either
skip a line, or skip an action (to avoid missing a line, pilots have a
tendency to touch the control but keep their eyes on the list, so they
don't actually confirm the step or even think about what they're
doing). Hence his preference for separating the roles of the two
pilots - read it (copilot role), do it (pilot role), check it (copilot
role) - into entirely separate sequences.

An oral checklist should be short and memorable. It should contain
only last-minute items and the few items most likely to cause death
and/or destruction. It can be used when the pilot is busy, because
it's short and doesn't require reading. In fact, busy moments - when
something may get overlooked - can be a good place to insert one! The
takeoff and landing checklists are the best examples.

I'm still working on how this translates for gliders. I think those
long checklists ("zipper check / chewing gum quantity check / attach
tow rope") are actually procedures: most pilots probably don't need to
keep using the written version (how likely is it that you'll forget to
attach the tow rope? - and if you do, what will happen?). Shorter
checklists have their place - "task set up on the nav computer" - but
probably should be done before you become #1 in line for takeoff. And
oral checklists should be used right before takeoff
("brakes-trim-belts" or whatever) and landing (USTALL, or your own
favorite) as a last-minute confirmation that nothing really stupid is
going to cause something really bad.

There's a somewhat separate question of what the right contents for
the procedures and checklists should be!