Went to a Garden Potty - S4-E20
Continuity mistake: When Karen is talking with Norman about donating funds for his advert, and then when Jack enters, between shots during the scene Karen's pearl necklace keeps jumping in and out of her black shirt. (00:45:00)
Continuity mistake: After Kevin throws the contract paper down onto Will's desk, the items on Will's desk, and the contract itself, change position a few times in the following shots. (00:27:05)
Visible crew/equipment: In Grace's bedroom, when Will says "c'mere you" to Jack, Jack runs over, and then Will pushes him out of the door. However, as Jack is running to Will, you can see the boom mike above them. (00:48:00)
Continuity mistake: When Karen sits down at the table saying "I get alot of cold water coming at me real fast..." between shots the slide box on the table changes position. (00:55:25)
Prison Blues - S4-E4
Continuity mistake: When Grace is in the bath, the remote control swaps what side of the bath it's lying on, and then completely disappears. (01:17:45)
The Third Wheel Gets the Grace - S4-E1
Continuity mistake: When Grace is standing in Barney's holding piles of clothes, as she says "he cracked under the pressure" the positions of all the clothes she's holding changes between shots. (00:19:25)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: When Jack is licking an envelope closed, standing by a large vase of flowers, the flowers change arrangement between shots. The sunflowers vanish and the poppies change place. (00:09:20)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: After Will looks into the mirror, after he puts it down it changes position between shots. (00:06:30)
Hocus Focus - S4-E24
Continuity mistake: Before Fannie starts the photo shoot with Will and Grace, she unbuttons the top of Grace's trousers. But later on in the shoot you can see they're done up, then later on they're undone once again. (00:34:00)
Continuity mistake: When Will runs in and takes a photo of Matt Damon and Grace kissing, to get evidence Matt is straight, when Jack pulls out the film from his camera, two boxes (a black and red one) vanish from the coffee table. (01:20:20)
Someone Old, Someplace New (1) - S4-E17
Continuity mistake: When Jack is making his film for Karen, as he's interviewing Grace, he holds a cheque book up to his mouth. Between shots the book randomly alternates from being in his right/left hand. (01:31:40)
A.I.: Artificial Insemination (1) - S4-E26
Continuity mistake: When the four are eating dinner and talking, Will says "Well I don't wanna sleep with you either," and in this closeup Karen picks up her glass of wine. In the next shot the wine glass is back on the table and she's now holding her fork. (01:14:35)
Loose Lips Sink Relationships - S4-E5
Continuity mistake: When Jack tells Karen to look away from the hand cream guy, a pair of trousers appears in her hands between shots. In following shots as well, the height of trousers piled on the table increases. (00:04:30)
The Third Wheel Gets the Grace - S4-E1
Continuity mistake: The stack of shoe boxes beside Rosario changes from when she begins to explain that she's been stalling Karen to spend time with her, to when Karen gives Rosie her credit card and makes a mad dash. (00:15:25)
Continuity mistake: When the gang are at Grace's mothers, Karen takes her pill whilst holding the bottle. In the next shot the bottle is out of her hand, on the side, and the cup she was holding has swapped hands. (00:12:15)
Continuity mistake: When Jack comes in the apartment, he has a fake mole on, that mysteriously disappears after Will leaves. (00:43:00)
A.I.: Artificial Insemination (2) - S4-E27
Continuity mistake: After Grace pushes Will, and he falls back and rolls over the bed, in the next shots the position and amount of rose petals on the bedspread changes, and the position of the pillows differs as well. (01:29:00)
Continuity mistake: When Beverley walks out of his hotel room to talk to Karen, he places a bucket with a champagne bottle in it, on the floor. In the next shot the bottle and white napkin are on the other side of the bucket. (01:15:10)
Continuity mistake: When Jack picks the wrong card, when his dad is playing "find the queen", the coat on the end of the bed changes position. (00:22:25)
Continuity mistake: When Matt and Grace are drinking mint tea, when Jack comes into the room to borrow Grace, Grace's mug of tea vanishes from her hand between the shots. (01:17:40)
Answer: A history of the game can be found at http://www.fast-rewind.com/bacon.htm.
J I Cohen