Inspired by Roman Hegglin's terrific Tower of Pi, I cobbled up a little program that makes various types of towers of letters. The long, thin tower is Lincoln's Gettysburg Address.Perl program reads an alphabet of 3D letters each as an STL file (such as you might export from Sketchup) and a sequence of ASCII letters. The program computes the STL file that is the sequence made into a tower. Piece of cake. Kudos to Roman Hegglin.