John Francis Daley, who played Sam Weir in Judd Apatow's brilliant TV series Freaks & Geeks, has signed on to co-write a new National Lampoon's Vacation movie. The new film is expected to see Chevy Chase reprise his role as Clark Griswold but will focus on Clark's son Rusty and his family. There has been no word as to whether other series favourites Beverly D'Angelo and Randy Quaid will return.

Daley is the latest Freaks & Geeks alumni to pen scripts for the big screen, following in the footsteps of Seth Rogen (Knocked Up), Jason Segel (Forgetting Sarah Marshall) and Mike White (School of Rock).

-John Balfe