Thankfulness Tag
This energy-burning game from Meaningful Mama's blog is great for families gathered for Thanksgiving as well as for Sunday school classes or Wednesday night groups.
Game play is similar to TV Tag, except the child being chased can sit down (and be safe and not be tagged by "It") by naming something that he or she is thankful for—that has not already been named by someone else. If someone is tagged or can't think of a new thing that they are thankful for before sitting, they become It.
Full description and rules (if a kids' playground game can have rules?) can be found at the blog.