The restaurant names that House reads off of the receipts (Knotty Pine and Richie's) are the names of actual restaurants in London, Ontario, hometown of series creator David Shore.
The word 'clinic' appears as a mirror image on the chalkboard. Also, the next scene has the word clinic in a mirror image in the clinic.
This episode reunites two actors from the film "Swing Kids": Robert Sean Leonard (Wilson) and Frank Whaley (Robert Elliot).