Anybody here tried this yet? How long did he/she stay in it? Can you move the circle somewhere else and get he/she to sit there too? The ultimate cat control. 
Nobody knows for sure why it works.
“If it fits, I sits.” --Every cat, ever.
Cats sit in things. They are drawn to enclosed spaces, probably for the same reason they generally like high places–a combination of security and territoriality. Many of the places they sit (open boxes, baskets, or these circles) aren’t actually any more secure, but they suggest enclosure, and that makes them appealing to cats.
Either that, or all these cats are collectively doing a Les Nessman homage.
I must have weird cats. Yeah, I know…all cats are weird, its a job requirement. I made a cat circle and they all ignored it.
OTOP, all cardboard boxes are magic and belong to the cats. For entertainment, I’ll put a small box on the floor and watch them try to squeeze their butts into it. I know, simple pleasures for simple minds…but have you ever watched a cat try to sit in a box that’s about the size of a coffee mug? 
Maru versus small boxes, for your viewing pleasure.
LOL! Good to know that I’m not the only sadistic cat owner around
Yep, it works (sorry for potato quality).
I watched the circle at first, but as the saying goes “A watched cat circle never attracts a cat.” In fact, Nibbler tried eating the circle at first, as per her name. But after I ignored it for a while, lo and behold I come back and she’s sitting in the circle. It’s magic.
Maybe the cat thinks the circle is a really short box. 
Those pics are cute.
I think this phenomenon will be perfectly understandable to any readers of The Dresden Files.
I attempted to make a circle out of a long shoelace. My cat pounced on it, bit my hand and tore off down the hallway with her prize (the lace, not my hand).
It was a great day for science.
I think my shoelace circle is under the couch. It was fun while it lasted, though.
After the above mentioned abortive experiment, I made one out of paper. So far, the only one who has noticed it has been my husband. “What the hell is that?” When I explained that our cats were part of a great scientific experiment, he just shook his head and walked away.
This merely demonstrates that your husband is not, in fact, a cat. Tell him that your new hypothesis is that he is a dog. Because SCIENCE!
One cat looked at me as if to say, “What the hell is wrong with you?” and stalked off (to sit in the wooden bowl that’s not quite large enough for her). The other tried to eat the tape. He likes tape.
I think mine are defective. 
When I read the thread title, I thought it was some New Age Techno-Pagan thing. Circles for cats, indeed. They’re always grounded and centered.
I’ll have to try it out on our three beasts and see. But our cats will always try to get into boxes, and they have a tendency to try to fit onto my books or magazines when I leave them on the ottoman. But I thought that was just to keep me from reading them.
Well, did he pee on it?
It’s not a circle, it’s a heptagon.
A pentagram might work better, though. 
For centuries cats have been trying to figure out why humans stare at them when they sit in a circle. The internet has advanced their research.
I get that reference!
Me too. 
If I made a cat circle, Tonka would probably urinate in the middle of it.
Combining these two comments, I have to ask - has anyone tried a cat square? Do squares work better than circles?
Thank you for this.
I have been watching Maru since I read this post earlier today. I am not getting any work done; but I am having a wonderful day.