I have written in the past about my practice that I call found haiku, where I search some preexisting text for phrases that fit the haiku rule of five-seven-five syllables. I've done several series in this vein, including haiku found in book reviews, junk mail, romance novels and newspaper stories.
At the moment I'm still working with the book reviews (although I think that project is nearing its end) and with a similar series, art reviews. In both cases, I make myself stick with the spirit of the original review; if the reviewer hated the book or the painting, I won't take favorable words out of context, or lift a comment that actually pertained to another book or painting.
Not that it's easier -- you can't believe how much I have to search to find some of the lines. My rule is that the entire five- or seven-syllable phrase must be found on a single line in the newspaper, so the narrowness of the columns acts as a handicap. (For instance, I would have loved to use the "Hawthorne-like allegory" in the last paragraph of this review, had it not jumped between lines.)
The art reviews involve another complication in that sometimes you find one review on each side of a page, so there's some back-and-forth, marking which phrases and photos to save and making sure the perfect phrase isn't smack in the middle of the perfect photo. And unlike the book reviews, which I often read simply to find my poem, I am deeply interested in the subject matter and read every word carefully, even reviews without a picture small enough for my little book.
The pile has been getting high in the last several months, and I wanted to attack it, so I took it with me to the retreat. And on the second day I managed to do 10 book reviews and 23 art reviews. This was a lot of reading, a lot of syllable-counting on my fingers, and a lot of cutting and pasting. I didn't exhaust the whole pile, but put a big dent in it.