Unconventional Formatting

Exactly What It Says On the Tin. A literary trope in which the text is arranged on the page in strange ways, including but not limited to: right-to-left (in Western works), bottom-to-top, reversed, upside-down etc. It can also make use of colours, and other

It can be done for a variety of reasons. A popular one is to represent a character's mental state, e.g. using cramped text to symbolize claustrophobia or feeling "trapped". Or, to just Think in Text: which is Exactly What It Says On the Tin.

Other writers may use it to visually represent the action being described in the text.
The technical name for this is ergodic literature, from the Greek ergon, meaning "work", and hodos, meaning "path" - that is,

A subtrope of Painting the Medium. Sometimes used in Meta Fiction and Scrapbook Stories. If employed throughout a work it may be a kind of Constrained Writing. See also Footnote Fever (with which this sometimes overlaps), All Lowercase Letters, No Punctuation Period, Rainbow Speak, Censor Box, Bold Inflation, Color Coded for Your Convenience and Page Turn Surprise.

Note: When adding examples, please be descriptive.

Comic Books

 * An original early Elf Quest comic had a hand-lettered foreword on the inside front cover in the shape of a wolf's head.

Fanfic

 * Whenever someone writes fanfic about a movie character that, ah, talks all . . . funny, like Heath Ledger's Joker, this, er, winds up happening. aND don'T EvEn MentIon dElIrIUm.
 * AnD tHeN tHeRe ArE tHe MsTiNgS wItH tOrGo.
 * Used in Forward to illustrate River's unbalanced state of mind.
 * "Riverthink" makes a guest appearance in Graveyard Shift, by the same author, to depict the message of the Prothean Beacon.

Literature
"The question was meant to be rhetorical, but his mind answered it
 * House of Leaves is possibly the most extreme example of this: multiple fonts, multiple colours, literally hundreds of footnotes, text which goes up, down, left, right, backwards, in spirals, sometimes only with one or two words printed per page and so on. It was so over-the-top the publisher's typesetters wouldn't even look at it, so the author Mark Danielewski had to typeset it himself.
 * Danielewski's next novel, Only Revolutions, makes use of other tricks like this: more extensive use of colours, a "sidebar" in the left margin of every page and... well, see for yourself.
 * Trainspotting uses slightly unusual textual layouts whilst the protagonist is.
 * Stephen King uses this from time to time: different fonts and typefaces, the intrusion of handwriting into typed text, and a device appearing in most of his works which makes use of italics, parentheses and sudden line breaks to represent character thoughts, as in this example from The Shining:

(you call it insanity)

nevertheless."

"They tramped on through the day.
 * Tristram Shandy is probably the Ur Example.
 * A favourite device of e.e. cummings, as can be seen here.
 * Terry Pratchett uses this quite often:
 * In Maskerade many readers were puzzled by a sentence fragment on the page, floating near the right margin saying "up here?". Near the bottom of the page a character is asked to demonstrate her skill in throwing her voice.
 * In Reaper Man Death who is famous for speaking in meets his boss, who speaks in "caps" so huge and bold they took up an entire page. Pratchett stated in interviews that he spent quite a bit of time arranging the prose so that this would happen on a left hand page and thus be a surprise to the reader. Reaper Man also uses two different typefaces for the A story and B story.
 * When the god Om regains his strength at the end of Small Gods, he speaks with chapter and verse numbers inserted between his sentences.
 * In The City of Dreaming Books, right after the villain is revealed, he hands the main character a book which will "answer all his questions" on page 333. As he flipps through the book, all pages are completely blank until he gets to page 333. The next two pages of the novel are completely filled with tiny letters that only say The next two pages of the novel are completely printed black with only a few words in white letters describing . You probably have to squint a bit and move the book close to your face to read it.
 * The Demolished Man uses unusual type layout to depict telepathic conversations (sentences trailing down a page and interweaving like braids; a party game where the image formed by the words is a kind of charade clue).
 * The Stars My Destination by the same author uses this trope as well.
 * In a style reminiscent of e. e. cummings, the novel Crank uses this on every page, with each chapter using a different format from the previous one. Its most prominent usage is in the use of space; the book is over five hundred pages long and takes a matter of hours to read.
 * The two sequels to Crank and the rest of Ellen Hopkins's subsequent books follow the same formatting style.
 * Good Omens mentions about a million styles of typography used for the title and multiple subtitles of Agnes Nutter's "nice and accurate" book of prophecies.
 * Jasper Fforde uses this a lot in the Thursday Next books particularly. Justified in that much action takes place in the Book World, with eraser bullets that reduce literary characters to text, locations like the Text Sea, and so on.
 * Fforde also uses this to graphically show what's happening in the text. Mycroft's Bookworms in TheEyre Affair produce apostrophes' as a waste product, as well as amper&s, and when they get upset, they hyphen-ate. These marks show up in the text of the dialogue to illustrate this.
 * Parodied in one of the Monty Python books where there's a self-referential page of coloured letters on a black background.
 * Concrete poetry is a poetic genre based around this trope.
 * In Search Of Adam by Caroline Smailes changes the placement of its words and shades of grey whenever Jude becomes obsessed over that thing in particular. For example when she's counting the words will zig-zag down the page.
 * Penn & Teller's Cruel Tricks for Dear Friends is printed in such a way that if you flip the pages front to back it's full of large fonted black print but if you flip it back to front it's full of tiny red print. This is used to trick your friend into believing that a special pair of cardboard specs (included) make things magically appear.
 * Not sure if this counts, but artist Tom Phillips made an art book called A Humument by altering copies of A Human Document, leaving only a few words visible per page and drawing a line to guide the reader in the correct word order.
 * The People Of Paper has an interesting one: some characters have the intrinsic ability to conceal their thoughts and actions from the author, and others can do so by lining their hat or their house with lead. In-text, this shows up as Censor Boxes over the concealed events (in some cases, entire pages of black).
 * Harlan Ellison complained about one author doing this in a story he submitted to one of the Dangerous Visions anthologies. It had entire manuscript pages that went something like:

Tramp

Tramp

Tramp

Tramp

Tramp

They tramped on through the night."


 * Ellison rejected the story but bought a more conventional one by that author.


 * On the other hand, he did publish Gahan Wilson's story whose "title" is a black blob, and which incorporates sketches of the blob getting bigger and bigger until.
 * The foreword to Kurt Vonnegut's Slaughterhouse Five is formatted to resemble a silhouette of a bomb.
 * "The Mouse's Tale" in Alice's Adventures in Wonderland winds down the page as if it were a mouse's tail

Web Comics

 * Homestuck is all about this. Every character has their own unique typing style that fits their personality (the humans doing subtle things like dropping initial caps or using different emoticons, and the trolls favouring Leet Lingo), certain Arc Words are written in specific (occasionally flashing) colours or with an animated gif replacing one of the letters, and at one point a character doing something around the back of the narrator speaks to the reader through Alt Text. The ==> command that indicates a new page is even replaced with ======> for the troll arc, to reflect the change from the four main characters to the twelve main characters (count the bars).