Continuity: Toward the end where the guitarist comes to talk to the kid at his house. He turns the chair around to sit in it backwards, but throws the shirt down onto the ground. When he sits down the shirt is back on the chair.

Factual error: The airplane that Penny Lane is on has small vertical stabilizers on the wingtips, which were not designed into commercial jets until the early 90's.

Factual error: It's 1969 and William Miller is looking through a bunch of very awesome vinyl records that his sister has given him, including stuff from Cream, Jimi Hendrix, and Bob Dylan. In the stash is Joni Mitchell's Blue. This is a mistake, since Blue did not come out until 1971.

Continuity: When Russell and William are walking together to "find something real" the VW bus containing the "real Topeka people" drives by behind them 2 times over their left shoulder before pulling up to them a third time on the right side.

Other: Penny Lane picks up William to go see Stillwater at the Riot Club in L.A.  In the very beginning of the scene in her car, a reflection passes up the windshield over William's face as they are driving.  The Reflection is the prism and spectrum from Pink Floyd's "Dark Side of the Moon" album.  There are no other reflections in this scene.

Factual error: This is a wardrobe error... in the next morning scene after William has been deflowered, he is still in his Fruit of the Looms, which have the name printed on the elastic waistband. Fruit of the Loom did not print their name on waistbands like this until the 90s, in the 70s they just had single blue and yellow stripes.