I use an embarrassing amount of canned pumpkin between the months of October and November and I've always wondered where the heck that stuff comes from. You hear a lot of calls for fresh ingredients from many bakers and cooks, but canned pumpkin seems to be a common exception to this rule.
Pumpkin puree is not harvested from your standard jack-o'-lantern pumpkin. They come from sugar pumpkins, which are much smaller and usually more oval or circular in shape (not squat like a perfect carving pumpkin).
I bought a sugar pumpkin on a whim at Trader Joe's (along with many other impulse purchases like greeting cards for no one, chocolate-covered espresso beans and my weight in cookie butter), and it sat on the countertop in my kitchen for a couple weeks. I mean, it made a very nice decoration, so I was in really no hurry to slice it open and scoop out its innards.