One of our favorite Vendors, Archetype (http://www.archetype-inc.com ) created this great Silverlight based Haloween greeting card.

You can carve your own pumpkin and send to your friends.

Try it, it is great (and is hosted on Azure): http://halloween.cloudapp.net/pumpkin/02a97183-d2c3-4b5f-a692-75c23da13703