Dawn said:

I'd like to let some go for seed for next year. How big is big enough? I
just got back from vacation and picked two that are longer than my arm (
my house-sitter ignored my request to pick them when they were small)
and the seeds still look small and white. Should I compost these and
try again? Or will they germinate after they have dried some?

Squashes are so prone to outcrossing that you could never be sure what
will result in the next generation. Zukes will cross with most pumpkins,
acorn squash (and several other types of winter squash), all sorts of
summer squash, and many gourds. You could end up with something
interesting, something completely dull, or something inedibly bitter,
hard-skinned, and warty.

To get ripe seeds, you'd have to let the fruit stay on the plant until
autumn. The stems would get to be like wood and the rinds very hard.

--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)