The scene where Emily and Oliver are standing naked behind the car and Oliver says to her that she just "looked" (at his genital area) hadn't primarily been shot for the movie. It was actually a real moment between Amanda Peet and Ashton Kutcher, which the director decided to use for the film afterwards.
Oliver (Ashton Kutcher) tells his sister Ellen (Taryn Manning) in a phone conversation at a party that he has just ran into her favorite rapper Eminem. Taryn Manning played Eminem's ex-girlfriend in the movie 8 Mile (2002).
Actress Birdie M. Hale, who was more than 90 years old during production of "A Lot Like Love" (2005), played the role of an old woman with a singular line ("Would you like to sit next to your girlfriend?") on a New York subway train early in the film. She had a very similar role as an elderly passenger on a New York subway train - also encouraging the two protagonists to get together - at the end of Coming to America (1988).