Salem's Lot (1979)

Cully's gun serial number.

Wet Hot American Summer

Just a timestamp. Still awesome.

The Girl With the Dragon Tattoo (2011, US)

Lisbeth is 23 years old.

Thanks Josh for the submission!

Rampart

Woody Harrelson's police car is # 232

The Dark Knight Rises (or whatever)

""Gotham has 23 days until the bomb goes off""

I wish it would, shitty stupid movie.

Urban Legend

The headmaster's license plate is 23019B.

Wayne's World 2

Check out the calendar ("I once knew a girl Gordon Street" scene).

The Time Traveler's Wife

Their winning lotto numbers include a 23.

Sunshine

"23 hours ago, while checking the comm systems..."

The Devil Inside

Isabella found the truth about her mother on May 23rd, 2009. Also, I believe Ben says he witnessed his first exorcism at 23.