The NYT did an interesting interactive story about the poster for the revival of La Cage aux Follies, which starts previews in early April. In it, Drew Hodges, the founder of SpotCo, the agency hired for the campaign, discusses seven drafts which ultimately developed into the eighth (and final) version. I always appreciate it when designers open up the creative process by revealing "failed" ideas since ultimately these drafts aren't failures but rather necessary stages in the development of a well-honed final product.
Listen to Hodges' audio commentary on each of the posters pictured above here: http://www.nytimes.com/interactive/2010/03/21/theater/20100321-lacage-interac...