While the old man walks up the stairs, he passes floor number signs "19" and "38". 1938 is the year Superman debuts in Action Comics No.1. Later, the character references the same year when he says, "...when I arrived in '38..."
In the coffee shop, the old man places a plastic container of coffee creamer on its side next to others already lying down. The arrangement the creamers are lying in make the letter "S."
The newscaster announcing the disaster in 1963 (played by the director's father) is an homage to Walter Cronkite's coverage of the Kennedy assassination.
There are several hidden "S" motifs throughout the film, including the path of cigarette smoke produced by the man in the coffee house, an "S" shaped door handle near the beginning, and every "S" in the opening cast and credits sequence (they all dissolve last).
As part of its marketing plan, writer/director Jim Cliffe quickly wrote and illustrated a prequel comic to Tomorrow's Memoir for distribution a week before screening TM at the 2005 San Diego Comic-Con.