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 Where Chandler Can't Remember Which Sister - S3-E11
Continuity mistake: Ross is on about going to Maryangela's to Chandler. He picks his drink up, the camera cuts and he picks it up again. (00:12:45)
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 Where No One's Ready - S3-E2
Continuity mistake: When Ross asks Chandler "you took his underwear?", the angle changes halfway through the line. Chandler's hands go from in front of him to being in his pockets. (00:10:50)
The One With The Dollhouse - S3-E20
Continuity mistake: After Joey walks away from the understudy and sits at the table, his hands are on the table but not touching; they are touching in the next shot. (00:07:50)
The One Where Ross And Rachel Take A Break - S3-E15
Continuity mistake: When Phoebe and Monica are at Monica's table and Phoebe is trying to convince Monica to go on a date with her date's translator, watch Phoebe's arm. She points at Monica when she says, "Don't call him that; his name is Spackleback Larry", but when the shot changes to a side view of them, she has her arm resting on the table with no time to put it down between shots. (00:06:25)
Continuity mistake: When Phoebe is talking to her stalker for the first time, at one point, he tips the flowers to the side when Phoebe says, 'Well, this is awkward,' and he puts his left hand on the end of the stems. In the next shot he is holding them with both hands. (00:02:55)
The One With The Dollhouse - S3-E20
Continuity mistake: When Joey is talking to the understudy, he is holding a cup. It disappears right when she invites him for a drink. (00:07:20)
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 Where Rachel Quits - S3-E10
Continuity mistake: In the very first shot of Chandler and Rachel sitting on the couch, Chandler has his legs crossed left over right, but it cuts to the closeup and his legs are crossed right over left, then it's back to left over right.
The One The Morning After - S3-E16
Continuity mistake: When Ross is listening to Rachel's message on his answering machine, only the open pill bottle sits on the counter beside his mug, but then the bottle cap and cotton filler suddenly appear next to it. (00:03:00)
The One The Morning After - S3-E16
Continuity mistake: While Monica's preparing her shake in the blender she asks Rachel about the anniversary dinner, and when Rachel tells her that she and Ross broke up, Monica throws the blender lid and it flies over the counter, but in the next shot the lid is back in Monica's hand, and then it vanishes again. (00:01:10)
The One Where No One's Ready - S3-E2
Continuity mistake: When Phoebe comes out of the bathroom after trying to get out the hummus stain on her dress, the bathroom door is left wide open. But when Monica is playing her message, the door is suddenly almost shut, though no-one had gone near the door.
The One With The Tiny T-Shirt - S3-E19
Continuity mistake: When Monica says, "I just recently got out of a serious relationship," she is holding her glass in her left hand. The camera cuts to Pete and the glass is now in her right hand. It then switches back to her left hand in the next wide shot.
The One With The Giant Poking Device - S3-E8
Revealing mistake: In the scene where Chandler confronts Janice about Joey seeing her kissing her ex-husband, Janice begins to hyperventilate. However, right before Chandler gives her the paper bag, Janice spins around and places the receipt in her mouth. Conveniently, after she begins breathing into the bag, she "chokes" on a receipt. (00:10:07)
The One With All The Jealousy - S3-E12
Continuity mistake: In the coffee house when Rachel is talking to Ross about trust, a couple comes in behind her and stands at the bar. In the next shot of Rachel they have switched positions; then they are gone, and you never see them walk past Chandler. (00:19:05)
The One Where Ross And Rachel Take A Break - S3-E15
Continuity mistake: During the dinner scene with the diplomat and translator, the men's glasses move closer, then further apart, and then closer together again. (00:14:20)
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 Giant Poking Device - S3-E8
Revealing mistake: When Monica and Rachel are banging their heads on the wood, it is clear that they aren't hitting them hard enough to result in the winces that are apparent. (00:09:00)
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.