The One With The Nap Partners - S7-E6
Continuity mistake: In the Maid Of Honour sequence, Joey's head starts to move one way. The camera cuts and it's no longer moving. (00:14:00)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Monica and Chandler are in Vegas waiting for the show to start, Monica's wrap goes from high up on her shoulders to half way down her upper arms between shots. This happens more than once. (00:12:40)
The One With Joey's Award - S7-E18
Continuity mistake: When Rachel walks in on Joey with the syrup bottle, he sets it down. In the next shot, he is holding it again. (00:05:10)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Joey is talking about all the different fabrics, the magazine Phoebe is holding keeps changing position. (00:17:00)
The One With All The Candy - S7-E9
Continuity mistake: When Phoebe tries to show the gang she can ride her bike, the large metal bike rack at the curb changes position between shots. (00:09:50)
The One With The Cheap Wedding Dress - S7-E17
Continuity mistake: In the shot where Joey meets Kristen the lights in the store window behind them are switched on. On the DVD at 05:19, you can see that the "CD" light is illuminated in blue. However, at 05:36 where they both shake hands, all the lights are switched off. (00:05:15)
The One With Chandler's Dad - S7-E22
Continuity mistake: When Ross is in the car with Rachel he sat in the back you can see him he has his arms crossed and then when the camera cuts to the front view he is holding the seat in front. (00:04:50)
The One With Ross and Monica's Cousin - S7-E19
Continuity mistake: When Monica comes into Phoebe's apartment for her Surprise Bridal Shower, the view of the hallway outside the apartment is a dead end on the right side (the left side cannot be seen), however, in S7:E12 (The One Where They're Up All Night), both when Phoebe is disposing of the fire alarm and when the fireman is at the door, it is clear that there is another apartment opposite hers, as well as a trash chute on the right side. (00:18:25)
The One With Monica and Chandler's Wedding, Part 1 - S7-E23
Continuity mistake: When Monica and Chandler are talking about what his father might wear to the wedding, the door to their bedroom opens itself and then closes itself between shots.
The One With All The Cheesecakes - S7-E11
Continuity mistake: Just after Rachel has tried to whistle and just blew out crumbs, she picks up the fork with her left hand and places it to the left of the cake on the kitchen counter. In the next shot just before Chandler picks up the cake the fork is back on the right side of the cake near her right hand. (00:16:05)
The One With Ross's Library Book - S7-E7
Continuity mistake: When Chandler says "lie" his hand is by his side, then up. (00:07:20)
The One Where Chandler Doesn't Like Dogs - S7-E8
Continuity mistake: When Chandler is looking over Ross' list (right before he calls him Magellan), he has the front sheet of the paper folded up. In the next shot, the sheet is folded down.
The One With All The Candy - S7-E9
Continuity mistake: In the scene where Monica's female neighbour comes begging for candy, after Monica gives it to her and shuts the door it's a man standing at the door not the neighbour.
The One With Rachel's Assistant - S7-E4
Continuity mistake: Ross has always said that Carol was his first (and only, until Julie) sexual partner, but in the episode where they tell each others secrets Chandler says Ross slept with the cleaner when they were at college. Some people say that Ross had kept it a secret, and that's why it had never come out before, but considering that he categorically states several times over series one and two how he'd only EVER been with Carol, getting quite upset at times, that explanation just doesn't ring true.
The One Where Rosita Dies - S7-E13
Continuity mistake: When Chandler and Rachel figure out that the chairs were switched they both head over to Joey's apartment. When they enter the apartment, the new black chair can be seen with tags attached to the top and left side. When the scene cuts to Joey sitting down the tags are all missing from the chair. (00:20:05)
The One With Monica's Thunder - S7-E1
Continuity mistake: When Rachel and Ross go to talk to Monica about why she doesn't want to talk to her, Chandler's tie changes, from on the bed to on his lap.
The One With Ross's Library Book - S7-E7
Continuity mistake: When Monica says, "she's not going to like that chicken either," Chandler's arms are crossed. Then the shot changes, and they're now by his face. (00:07:50)
The One With Phoebe's Cookies - S7-E3
Continuity mistake: When Chandler and Jack are placing their robes on the hook, they change positions when Jack looks at Chandler naked. (00:19:39 - 00:20:08)
The One Where They All Turn Thirty - S7-E14
Continuity mistake: In The One Where They All Turn Thirty, it is Rachel's birthday. They show flashbacks of all the other Friends' thirtieth birthdays despite Monica's birthday supposedly being months after Rachel's. Plus, earlier on in the show Joey was 25 when Monica was 26, and since Monica and Rachel were in the same grade Joey should actually be a year younger than them, not a year older.
The One With All The Cheesecakes - S7-E11
Continuity mistake: When Ross and Monica are at the wedding reception talking to the other guests at their table, a lady wearing a red scarf is standing behind them with her back turned. Throughout the scene the red scarf keeps changing position very quickly - in one shot it's slid down one shoulder, then back up in the next and then slid down again. At the end of the scene it's off her back entirely and she has just slung it over her arms. (00:12:15 - 00:13:15)
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.