The book from which Kyle is reading at the book-signing switches between hardback and paperback.
The paper coffee cup appears to be from Starbucks when Ethan is holding it in the kitchen, but when placed on the breakfast tray outside, it's clearly a different color and brand.
The magazine Ethan's holding in the elevator jumps from hand to hand between shots.
Leo, when handing Ethan the "save-the-date" card, tells him that he and Chester Baer will hold their commitment ceremony on June 1. In the next scene, when the Hat Sisters are reading the card, it reads "the second day of August."
In the book store scene at the beginning of the film, in the close-up of the gay Republican, the film is flipped, as you can tell from his shirt buttons being on the other side and the "SALE" sign behind him being reversed.