"Filler" text is used when a design must be shown to an audience and body copy remains unwritten. Text shown in the audience's native language will inevitably be discussed; potentially it can also influence client's impressions. In these cases, "dummy text", complete with punctuation and capitals, substitutes for real text. The result is a page with text that looks complete but has little danger of misinterpretation or distraction.
Traditionally, the filler text used is Lorem ipsum, which consists of fragments from the first book of Cicero's De finites bonorum et malorum, a discourse on hedonism, written in 45 BCE. Lorem ipsum was first used for this purpose over 500 years ago, during the age of Gutenberg; it gained popularity after being featured in Letrapress in the 1960's and Aldus Pagemaker (one of the first successful desktop publishing programs, developed for the Apple Macintosh) in the mid-80's.
Web designs have need for a greater variety of dummy text than traditional typesetting, as we frequently deal with lists, tables, and other data structures. To this end, one of the earliest lore ipsum generators remains the best, and is still my personal favourite. However, there are a few alternatives that you might find interesting:
Blind Text Generator has a few more options, and can generate CSS to match the filler text.
html-ipsum has pre-packaged paragraphs, lists and forms of filler text with markup already in place.
If you're tired of lorem ipsum, you can create random text from television shows and advertising jingles with Text Generator.
Dummy Lipsum is a plugin for Firefox that generates lorem ipsum text with markup.
You can go gangsta with lore ipsum, or talk like Samuel L Jackson on your site, our use Lebowskiipsum to really tie your page together, man. (Just use the clean versions of both for work in my class, please).
My new personal favorites have science fiction and technology themes: Robot Ipsum and Space Ipsum.
Corporate Ipsum is a widget for OS X that auto generates paragraphs of filler text based on popular corporate speak, such as "Compellingly parallel task cross-platform growth strategies and highly efficient strategic theme areas."
If you don't believe they've sold out already, Hipster-ipsum generates filler text for hipsters.
For foodies, Baconipsum generates meat-associated Lorem Ipsum, while Tuna Ipsum does the same for seafood. For vegetarians, there is Veggieipsum and VeganIpsum. If baking is more your thing, there's Cupcake Ipsum. And if you want to go the whole hog (ahem), and put actual bacon on your page, simply precede the URL with http://bacolicio.us//: for example, http://bacolicio.us//http://baconipsum.com
If you're feeling more in a political mood, you might want to try the random right-wing ravings of Tea Party Ipsum.While not exactly Lorem ipsum, the excellent Elsewhere.org blog offers a Postmodern text generator, which generates post-modern critical analysis filler text that includes headers and lists, and an adolescent poetry generator; related, the Arty Bollocks Generator and Design Quotes Generator. Also on Elsewhere.org, a random band name creator and random text samples from Time Cube.