The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When they are in the coffee house talking about the fact that Joey missed his audition, Phoebe says, "And that is why we don't invite you to play." Her hands are at chest height, but in the zoomed out shot, they are lowered. (00:02:50)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: The position of the lid of Janice's box of contact paper changes repeatedly and after she tells Chandler she doesn't know what to say, she begins to slide the roll of paper back into the box. In the shot from behind, the box is closed. (00:09:50)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When Rachel and Monica are comforting Chandler, just before he gets up Rachel has her hands on the chair but when Chandler gets up Rachel's hands change position. (00:12:40)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When Chandler is getting relationship advice from Monica and Rachel near the end, the label on the ice cream tub he is holding changes position depending on whether the shot is close up or not. (00:13:00)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When Ross shows G.I. Joe to Ben, the Barbie's legs are pointing towards the refrigerator. In the next shot, they are suddenly pointing the opposite way. (00:13:50)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When Monica is telling Susan and Carol that Ross used to dress up as a girl, Ross goes over to the table and picks up a drink. When he picks it up it has a cork in it. In the next shot he has the cork already in his hand. (00:20:30)
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: While everyone's watching Joey's commercial for the Milk Master 2000, the TV area changes in the closeups.
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: When Ross is singing to Ben about GI Joe, there are two plates in the dish drainer behind him, but when Joey walks in and sits down the white plate has vanished.
The One With The Metaphorical Tunnel - S3-E4
Continuity mistake: In the scene where Chandler is sitting on the cabinet talking to Rachel and Monica, Rachel is holding an ice-cream bucket and a spoon. However, they keep showing up on the counter and then back in her hands between shots.
The One With Frank Jr. - S3-E5
Continuity mistake: In the scene where Joey and Monica discuss changing her bathroom tile, Joey moves the hamper to the middle of the doorway and when he kneels down to measure, the hamper is back against the wall. (00:06:25)
The One With Frank Jr. - S3-E5
Continuity mistake: When Phoebe is talking to Monica while Frank Jr is doing karate on the balcony, the blue cup in front of her moves, disappears and is back again. (00:10:20)
The One With Frank Jr. - S3-E5
Continuity mistake: When Frank Jr. holds a white sheet around himself, while talking to Phoebe about how she really is a masseuse, etc., the gathered sheet in his hand keeps changing repeatedly throughout the scene. (00:14:10)
The One With Frank Jr. - S3-E5
Continuity mistake: When Frank has the towel wrapped around him, the knot on his chest changes a lot between shots.
The One With Frank Jr. - S3-E5
Continuity mistake: When Frank is trying to melt a spoon there's one shot where he holds the spoon high above the table, then the angle changes and he's pressing the spoon against the plate.
The One With The Flashback - S3-E6
Continuity mistake: When Ross is talking to Phoebe and puts shot glasses on the bar, they're in groups. In the long shot, they're in a straight line then in a closer shot they're in groups again. (00:17:20)
The One With The Flashback - S3-E6
Continuity mistake: Phoebe and Ross are in the soon to be closed bar sitting on the pool table. He clears it of everything, but a few seconds later he stops making out because the "damn balls are in the way" and somehow magics up a handful of snooker balls. If you look closely when he's clearing the table, there are two dark balls at the side which he studiously ignores, and which Lisa Kudrow then surreptitiously grabs and takes onto the table with her so David Schwimmer can grab them later. (00:19:35)
The One With The Flashback - S3-E6
Continuity mistake: When Ross and Phoebe are in the bar and get on the pool table to start kissing, Ross moves the pool balls out of the way, but two remain. As Phoebe lies down, the 9 ball is next to her left shoulder. The shot cuts closer and it is the 13 ball, then cuts back and it's the 9 ball again. (00:19:40)
The One With The Racecar Bed - S3-E7
Continuity mistake: In the scene where Joey's teaching soap opera for actors, his name changes from the 'a' being on the line to being above it. The line itself also reaches the far right of the board in some shots, and is short of it in others. (00:06:00)
The One With The Racecar Bed - S3-E7
Continuity mistake: When Monica and Rachel show Ben them banging their heads against the wooden beam in the kitchen, Phoebe is hovering on the phone in the background when she is supposed to be at the dentist's office. (00:14:13)
The One With The Giant Poking Device - S3-E8
Continuity mistake: At the start, Phoebe snaps at Rachel that she will go to the dentist. When she says this, her grip on the apple in her hand changes between shots. (00:02:30)
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.