I discovered by doing this project how few real stamps come on our mail these days. I think that is sad. I love my mail during the holidays with all those cheerful stamps. Since I didn't have enough postage stamps for my project, I made some of my own using a couple of "stamp" clear stamps. This is a great option especially if you would like your project to be archival.
Be sure and check out If It's Groovy to see all of the design teams' take on the challenge.