Ted wonders aloud if there are three Parises in Ohio. There are indeed three townships in Ohio called Paris, in Portage County, Stark County and Union County.
The busker playing 'Hey Jude' is Danish artist Alex Vargas.
The outfit that Keely buys to wear to the polo match was a brown dress with white polka dots and a white hat. Julia Roberts wore a very similar outfit in the polo scene in Pretty Woman.
The episode title is a reference to a quote from the film "Casablanca". The quote is "We'll always have Paris".
When Ted tells Rebecca about the possible Paris destinations that his ex-wife may have gone, the first one he mentions is Paris, Texas. This could be seen as a callback to the film of the same name which tells the story of a man taking care of his son during a road-trip in search for his estranged wife.