Absolutely nailed it in cartoon form.
A most excellent thread. Thanks Opalcat.
Willow in a box.
Willow in a lunch bag.
Piper in a take-out style box.
Maeve in a basket.
Willow in a magazine box.
Cats is funny.
Here’s a picture of our Squeaks:
http://i11.photobucket.com/albums/a186/GinaHendrixson/FurBabies/sambox.jpg
Baggins in his hideybox:
http://i11.photobucket.com/albums/a186/GinaHendrixson/FurBabies/Baggins2.jpg
Kittens from the stray my husband brought in, in their Rubbermaid box:
http://i11.photobucket.com/albums/a186/GinaHendrixson/FurBabies/kittens2.jpg
Basement Cat’s preferred mode of transportation. 
My Bella does this. We call her hamster-kitty. I recently went on a cleaning spree, and let me tell you, I now find her cardboard knawing less cute than it was previously.
We have one of those cardboard scratch-pads and the cardboard shrapnel kind of takes over the room. Fortunately they don’t chew on cardboard that often.
No cat box pics yet for you, but I couldn’t resist clicking through your pics…you know Kitty Karma is going to pounce on you for this, don’t you?
http://gallery2.opalcat.com/gallery2/v/Miscellaneous/Animals/Cats/Cory/kitty_costumes_008.jpg.html
When our daughter was still living at home, we had to keep a shoebox in the living room, under the stereo cabinet. If we didn’t, Achilles (one of her cats) was most unhappy, and would sulk until we put another box under that cabinet.
I’m pretty sure that my daughter keeps a shoebox around in her apartment, just so Achilles won’t sulk.
He really doesn’t mind when we dress him up. It’s hilarious.
By the way, the thread was originally called just
Cats in Boxes
and I requested that it be changed to
Cats in Boxes (pictures of!)
and ended up with
Pictures of Cats in Boxes which isn’t quite as snazzy as I’d hoped 
I’m so glad I started this thread. All the pictures of cats in boxes is getting my squee on!
The obsession began when she was only 4 weeks old.
When she hears the UPS truck, she runs to the door and demands the box be opened and emptied of it’s contents. If I’m not fast enough, she tries to do it herself.
Here, you can see the teeth marks where she tried to kill the flaps.
Since people have moved on to other containers already, I’m going to present Desdemona in a bowl, and in bags.
Heres one of my late cate in a cat tent.
She had the whole room to herself, she was spoiled rotten. She owned us.
Posting to subscribe and remind me to upload my pics.
I shop at a warehouse club on occasion and one time I brought stuff home in a box with high sides and back but a low front. Within seconds of unloading tge box the cats were fighting over it. The box was never without a cat. So I pick up a new one of the boxes everytime I go to the club. I have several now, the boxes were for huge bags of whey protein and they come in chocolate and vanilla. I have two boxes on a table side by side and I managed to get some pics of my mostly white cat in the vanilla box and a black cat in the chocolate. In another pic the brownish tortie was in the chocolate box.
Feather in a box. I should get a picture of her in the laundry basket, too - she jumps in it the second it’s empty, then wants to get picked up and swung around in it. It’s her version of a carnival ride.
Nobody can do, “I’m putting up with it now, but I’m going to kill you in your sleep later” as good as cats.
Here is Soda Monster in a bio-hazard bin looking cute and not very hazardous.
And here is one of our cats (I can’t tell which one) looking rather grumpy in a cat cube.
We have my wife’s family’s Scrabble game from her childhood. They played often, and whenever they did, the much-beloved family cat would come out and sit in the inverted box lid, witnessing hundreds of games of Scrabble over the years.
The cat is long since gone now, but the first time we brought the game out after moving it to our house, our sweet little kitty promptly came out and sat in the inverted box lid, silently watching our game (my wife won).
My wife was incredibly touched. 