If a reference can't be cited using MLA (or Chicago), does it really exist?
For example, say you have a Kindle or an iPad. I've been given an iPad as a present--yay!--so let's stick with that as an example. You can download books from the Kindle store on Amazon.com, if you put the free Kindle app on your iPad. You can also buy or download books from the iBooks store, including free public domain ones. The thing that doesn't come along with these nifty editions is a set of page numbers that corresponds to the page numbers in the original text.
That's not a problem with .pdf documents, since they're images of the original. You can read them and, since Sept. 30, annotate them using the GoodReader app, or read and annotate them using iAnnotate. You can copy text from the .pdf and paste it into Docs-to-Go.
So far, I like the experience of reading on the iPad. If you have a book with endnotes, for example, the endnotes are links, so you can click on the note and then click back to the text. You can write notes in both the Kindle and iBooks apps, although I haven't explored that much because it's harder than I thought it would be to type on the screen-based keyboard.
What if you want to cite a book that you've downloaded? Kindle books--for scholarly books, anyway--cost about the same as the paperback edition, and they cost more than a used copy, so if I'm going to shell out the money for one, I want to be sure that I don't need to get another copy.
The piece of advice I've found most often is "go get a print copy of the book, find the citation, and cite the page." This is probably the best advice for now, but it's a colossal timewaster and a duplication of effort to have to hunt up the book if you've already bought it. If the book is in Google Books, you could try searching for the phrase in there, but a lot of books aren't in Google Books.
APA has addressed this by suggesting that you cite is as you would any unpaginated material: "Name the major sections (chapter, section, and paragraph number; abbreviate if titles are long), like you would do if you were citing the Bible or Shakespeare." Since paragraphs aren't numbered, I would be less than thrilled to have to scroll through and count the paragraphs just so I could cite the reference. And what about paratextual elements such as epigraphs? Do they count as paragraphs when you're counting?
Some other sources suggest that you cite the Kindle location number, which would be swell if the editor of the journal you're submitting to has a Kindle and not so much otherwise.
The Chicago Manual of Style suggests just citing the Kindle edition and maybe the chapter number.
The MLA Handbook for Writers of Research Papers, Seventh Edition floats above the fray by saying (in 5.7.18) that you should just say what kind of file it is: "Microsoft Word file, JPEG file" or whatever. Presumably you could say "Kindle file" or "iBooks file" there, too, although all of the examples given are for short pieces. That wouldn't provide much information if you were trying to cite from a book-length source. As EduKindle asks, "Why is it so hard to cite a passage on a Kindle?"
Beats me. I'll be happy when MLA gets this straightened out, almost as happy as I'll be when they decide to jettison those #@%$& angle brackets that they make you put around a URL (see 5.6.1) as though we'd all just stare helplessly at an http:// prefix without knowing it was a web address unless it was safely contained in a set of angle brackets. [Edited to add: tenthmedieval has a good explanation for this in the comments.]