If your squash shells are suitable, you can serve your soup using the shells as a bowl (small sugar pumpkins work well for this task, as well). (healthygreenkitchen.com)
I have a couple of sugar pumpkins that I bought at the grocery store that I was trying to figure out what to do with - think those will work? (101cookbooks.com)
I used a roasted sugar pumpkin in place of the canned pumpkin. (browneyedbaker.com)