Factual error: Julia Roberts character orders Pizza and Wings, gives the driver one bill (guessing it's a $20). Says she's giving a $12 tip. No way Pizza and Wings costs $8, certainly not in California.
Continuity mistake: In the scene where Julia Robert's character gets on the back of Tom Hank's character's scooter, she is first seen wearing a green helmet with red/white stripes on it. Later in the same scene she is wearing an all black helmet.