Jennifer, who lives a fairy tale boat life, had the wonderful idea of turning the Corporal and Spiritual Works of Mercy into a living project. She combined a study of several saints with learning about the various works.
Tying each work of mercy to a particular saint is sure to make knowledge of the works stick in the kids' minds. We've already begun this project (though we decided to do it in book form instead of as a tower) and my girls are enjoying it immensely.
See this thread on the 4Real forum for details. Jennifer, thank you for doing all the research and legwork for us ... All we have to do is click, learn, and create!