Onder andere met: Will Ferrell (Harold Crick), Queen Latifah (Penny Escher), Peter Grosz (IRS Co-Worker #5), Ricky Adams (Young Boy), Christian Stolte (Young Boy's Father), Denise Hughes (Kronecker Bus Driver), Peggy Roeder (Polish Woman), Tonray Ho (IRS Co-Worker #6), Tony Hale (Dave), William Dick (IRS Co-Worker #1), Maggie Gyllenhaal (Ana Pascal), Danny Rhodes (Bakery Employee #1), Helen Young (Bakery Customer #1), David Pompeii (Bakery Customer #2), Linara Washington (Bakery Employee #2), Dustin Hoffman (Professor Jules Hilbert)