The One Where Rachel Has a Baby, part 1 - S8-E23
Continuity mistake: At the beginning, when Rachel first arrives at the hospital, she is talking about the hospital not being out of rooms. She points to herself with her right hand saying 'What if I was the president?' Then when the shot changes to include Ross she is pointing to herself with her left hand, then it cuts back to just Rachel and she is using her right hand again. (00:01:25)
The One Where Rachel is Late - S8-E22
Continuity mistake: The first time Phoebe and Monica are making bets on when Rachel will give birth, Phoebe has a bottle of water in her hand and is holding it near her stomach. She puts it to her mouth to drink some, but in the next shot, the bottle is near her stomach again. (00:07:00)
The One With Rachel's Date - S8-E5
Continuity mistake: When Ross asks Rachel how the date went, she grabs the bag she is holding. Next shot she is touching her coat. (00:18:20)
Continuity mistake: When Joey and Chandler are discussing Joey's shoes, the length of the sleeve round Joey's neck changes depending on the shot. (00:11:20)
Continuity mistake: When Monica and Rachel are discussing Phoebe, Rachel's hands go from playing with the table to dry washing depending on the shot. (00:12:30)
The One With The Rumor - S8-E9
Continuity mistake: When Rachel is offering Will the yams, the spoon that's in the dish is facing Rachel. When the shot changes to Joey lifting up the Turkey, the spoon is suddenly on the other side of the dish and facing towards Will. (00:11:05)
The One With The Stripper - S8-E8
Continuity mistake: When Ross and Mona are having their "make-up" kiss, Mona puts her left arm around Ross's neck, then in the next shot she does it again. (00:18:50)
The One With The Halloween Party - S8-E6
Continuity mistake: When Rachel returns from running after the boy that she told to "shut up", you see Joey picking up a piece of food, sniffing it and making a face and then putting it back on the tray. However in the next shot, without moving, Joey is munching on something - he didn't have anything in his hand before. (00:19:55)
The One With The Video Tape - S8-E4
Continuity mistake: At the end, Monica goes to dial a number, the camera changes and she has dialed with no time. (00:22:20)
The One With The Halloween Party - S8-E6
Continuity mistake: While Phoebe is calling out Ursula for lying to Eric, her hair continuously changes position from behind her shoulder to in front of her shoulder depending on the camera angle. (00:14:50)
The One With The Baby Shower - S8-E20
Continuity mistake: During the mock Bamboozled game with Chandler and Ross, when Joey asks about the word triskaidekaphobia a bottle of Evian suddenly appears on the countertop oven, which vanishes and then reappears.
The One With Joey's Interview - S8-E19
Continuity mistake: In the opening scene Rachel is holding a white felt pen in her hands and gesturing with it while she talks about the soap opera digest magazine. Between shots the pen sometimes has its cap on and then it's off again so you can see the blue tip. (00:00:20)
The One With The Video Tape - S8-E4
Continuity mistake: When Rachel is finding out that people know the Europe story, hers legs keep changing positions. (00:19:15)
The One With The Tea Leaves - S8-E17
Continuity mistake: When Pheobe is reading the tea leaves, Chandler lowers his cup. The camera cuts and he lowers his cup again. (00:04:30)
The One With The Halloween Party - S8-E6
Continuity mistake: When Chandler and Ross are arguing, the nose on Chandler's costume moves. In one shot it's on his chin. The camera then cuts to Joey and Monica and back, and then it's down round his neck. (00:12:20)
The One With Rachel's Date - S8-E5
Continuity mistake: At the end when Rachel comes into the coffee house and sees Mona with Ross, she is holding a brown paper bag. When you see her in the background, the the top of the paper bag is rolled over away from her. When the camera switches to just Rachel, the paper bag is the other way around with the top rolled over towards her. (00:21:35)
The One With The Cooking Class - S8-E21
Continuity mistake: The night before they go to the baby furniture store, Ross and Rachel are in the kitchen talking. Just before they leave the kitchen watch Rachel's robe: in one shot the 'lapels' are neatly one over the other, and in the next shot one lapel has moved lower and looks halfway folded over as if she hastily pulled the robe together. (00:03:15)
The One With Rachel's Date - S8-E5
Continuity mistake: When Rachel asks what Kash said, her arms are outstretched, the ext shot they are together and when the camera cuts again and they have moved yet another time. (00:06:55)
The One Where Rachel Tells... - S8-E3
Continuity mistake: When the airline representative states the first class seats are gone, her head leans away from the camera. The shot changes and it's leaning to the camera. The camera is in the same place. (00:07:10)
The One Where Rachel Tells... - S8-E3
Continuity mistake: When Rachel and Ross are at his apartment, Rachel is holding some magazines. The way she holds them changes depending on the shot. (00:09:35)
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.