In the hobby store, when Mark checks out the miniature medals, the Purple Heart he buys has a reference label next to it reading CRM-114. CRM-114 is a piece of radio equipment in Stanley Kubrick's "Doctor Strangelove". The code has then been used by Kubrick in latter films and by other filmmakers as a tribute to him.
The trivia items below may give away important plot points.
Deja asks Mark to make a time machine and asks for it to fly. The time machine he makes resembles the DeLorean from the Back to the Future series, including the wheels that rotate to make the car hover. Both films were directed by Robert Zemeckis, and both films were scored by Alan Silvestri.