Jack Klompus (Sandy Baron) first says that the bill for his and his wife's dinner was $19.44, but later changes it to $19.45.
The pen shown in this episode is the bullet pen, made by Fisher. Although it does write upside down and in extreme temperatures, the bullet was not the pen used by NASA and taken into space. It was Fisher's AG7, a retractable pen and the first one invented by Fisher in 1966, that NASA used on all manned space flights.