When Dean calls Jesse he identifies himself as the person who reads "Franzen," referring to the book he is always carrying, an author that both he and Jesse enjoy. But, in the hospital scene, the author of the same book is clearly Foster Wallace, that is not mentioned except to say that he killed himself. Franzen is alive and well.
Just before and after the first hug scene of Jesse and Zibby in the theater, when they are walking together (to and fro), we see a girl in grey top and black pants walking in the same direction twice.
At the very beginning of the film, during the series of quick cuts denoting the passage of time, none of the items on any of the furniture change positions.
One of the early listings in the final credits is missing an "s" - "First Assitant Camera."
When listing the music tracks at the final credits, "Mediation" by Jules Massenet is written. It should be "Meditation."
At 1:06, Jesse calls Zippy "Elizabeth."