Great Moments in Fabric Literature, Vol VII

This left only one parcel. Harry picked it up and felt it. It was very light. He unwrapped it.
Something fluid and silvery gray went slithering to the floor where it lay in gleaming folds. Ron gasped.
"I've heard of those," he said in a hushed voice, dropping the box of Every Flavor Beans he'd gotten from Hermione. "If that's what I think it is - they're really rare, and really valuable."
"What is it?"
Harry picked the shimmering, silvery cloth off the floor. It was strange to the touch, like water woven into material.
"It's an invisibility cloak," said Ron, a look of awe on his face. "I'm sure it is - try it on."
Harry threw the cloak around his shoulders and Ron gave a yell.
"It is! Look down."
Harry looked down at his feet, but they were gone. He dashed to the mirror. Sure enough, his reflection looked back at him, just his head suspended in midair, his body completely invisible. He pulled the cloak over his head and his body vanished completely.

J.K. Rowling, Harry Potter and the Sorcerer's Stone, 1997, pg 201

Invisibility cloaks, caps and other magic articles that render the user invisible abound in literature since the beginnings of literature. There was Hermes' magic cap, also H.G. Wells' Invisible Man, and many, many other examples.
For Harry Potter aficionados, the introduction of the invisibility cloak is a vital plot point. This cloak will make many appearances (disappearances?) throughout the story.
I first heard J.K. Rowling read from her book in an interview on NPR back in 1997, while I was driving home from work. She read the chapter where Harry goes to the zoo on Dudley's birthday, and it was so amusing and interesting that I went to Olsen's Bookstore the next day at lunchtime and bought two copies - one for my kids, and one for my nephew, for Christmas. When we opened presents, the kids (of course) had never heard of Harry Potter. So we read it aloud to each other that whole Christmas vacation. This is a book that should be read aloud to and with children, and we all three took turns reading it to each other. The story really isn't fully appreciated unless it is shared. (Especially the Uncle Vernon parts)
Go read it again - J.K. Rowling is so inventive it is a pleasure to imagine Every Flavor Beans, Chocolate Frogs, Grow-Your-Own-Warts Kit and more.

Invisibility cloaks might soon be more real than you think. Check out what they are up to at the University of California.
(Take that, Stanford! Go Bears!)