In the Southern USA, the pineapple is a traditional symbol of warmth and hospitality. After a little more research I have discovered that the use of a pineapple to symbolize "Welcome" goes back to the Carib people, pre-Christopher Columbus. It then spread to Europe, then Colonial America.
You can see a mock-up of the banner at Flickr. For some reason It won't link to the Flickr page so here's the link:click here