Continuity mistake: As House describes the lady's symptoms, in the front shot Chase has a small book/pamphlet in his hand. The camera changes to a side shot in the middle of House's description and suddenly the book is on the table and no longer in Chase's hand. This happens right in the middle of House's line and Chase doesn't make any quick movements to account for this discrepancy.
Continuity mistake: As Cuddy is making the deal with House, how much time off from Clinic duty for a week off his vicodin, while the camera is behind Cuddy you can see there is bright sunshine on House's head. The shot switches to a camera behind House and now his head is shaded.
Continuity mistake: House is about to inject Ezra Powell (Joel Grey) with what is supposedly a lethal dose of morphine. In the shots where they pan out to show House addressing the room at large, the syringe is very full, almost completely. When they zoom in on House holding the syringe, it is only filled a fraction of that much - maybe a quarter to a third. This doesn't happen just once, but every time they switch between shots.
Continuity mistake: During the scene where Dr. Chase and Dr. Cameron are out having a drink, Cameron picks up Dr. Foreman's cell phone. Before she does she takes a drink of her soda. This drink drops the level of drink to half full. When Foreman returns a few seconds later she suddenly has a glass that is 3/4 full. There was no time for anyone to give her a refill.