Cento hails from the Latin word for 'patchwork,' and has been around since at least the 4th century. It is basically a poem made up of lines from poems by other poets. Each line must be taken from a different poem. and when the lines are put together, they must make sense. The poem doesn’t have to rhyme, but rhyming adds a nice touch. And always give credit to the poets you use.
One of my professors insisted we write these as a way of proving that we were familiar with a broad array of poetry. At first I hated it but it became a fun challenge and as an added benefit I found myself immersed in poetry I might have otherwise overlooked. (I'm sure that was entirely unintentional)
Here is a great example by Simone Muench called:
Wolf Cento
Very quick. Very intense, like a wolf |
Octavio Paz, Henri Michaux, Agnes Nemes Nagy, Joyce Mansour,
William Burroughs, Meret Oppenheim, Mary Low, Adrienne Rich, Carl Sandburg]
The twist is "Book spine poetry."
It has been around for a few years and if you google it you can find tons of examples by a wide range of people: students, teachers, children, adults. It's as easy as you want to make it.

This one is by Travis at 100 Scope Notes.
Look Who's There!
The Watcher
What Do You See?
More
People

Lorne Daniel at Writing:Place created his book spine poetry from poetry books.
What Goes On
Here and Now
A Long Continual Argument
The Poet in the World
Writing Down the Bones
Refusing Heaven
I made my own book spine poem, but technical difficulties have kept me from uploading the picture. (lost cabely thing)
It was fun playing with the books in my own library to create a poem. I think kids would really enjoy this and I can see it as a way to jump start creativity in a dry spell.
I'll admit though, it would have been more fun if I had someone to clean up the mess I made.
Do Androids Dream of Electric Sheep
Reading Lolita in Tehran
A Passionate Apprentice
Wicked
Insecure At Last
East Wind Melts the Ice
[Sources: Philip K. Dick, Azar Nafisi,

How to:
Create a Cento
1). Take the time to look through a few poetry books. Enjoy the poems.2). Find a line you especially like, and make that the first line of your patchwork poem. Write the poet’s last name in parentheses at the end of the line.
3). Repeat #2. Choose your lines carefully—your poem must make sense.
Some things to consider:4). And remember, at the end, list each poet’s full name. Include the name of the poem in quotes.
Try to make your poem rhyme.
Make sure the beats sound right.
Tenses should agree.
Person should agree. In other words, pick lines that have all been written in either first or third person.
1). Find a place with plenty of books: a library, home collection, or even a book store (if they'll let you).
2). Find titles that strike you and write them down – you can refer back to them later.
3). Arrange and rearrange them (in your head or on paper).
4). The Library card catalog can help you find titles with specific words or phrases that fit.
