Wishing everyone a most joyful thanksgiving, I come to think of similar festivals about giving thanks to life's bounty. The most prolific is the Chinese Mid-Autumn Festival, also known as the Moon Festival or Lantern Festival. Harvest Festivals have been around since pagan times and is appropriate for most fantasy games. I recall a short adventure in the Polyhedron magazine where the characters are hired as 'turkey herders' to help get the turkeys to sale. Combine this with an autumn festival and you have a Thanksgiving inspired theme. How do you portray festivals in your games?