More and more, I've been using Amazon.com as a research tool. With books increasingly searchable, it makes sense to use such a commercial site to gain a quick overview of, say, the citations in a given book, or skim a table of contents to find out if the writing's pertinent to my needs.
Even more useful to me, though, is the ability to search for specific quotations in a work and have the page containing a phrase displayed. Say I want to know on what page, and in what context, Stephen Dedalus asks "Is this old wisdom?" Rather than thumbing through Ulysses around where I expect to find my quotation, I'll check if Amazon's "search inside" feature is up for my edition of the book.
I'm hoping digital libraries will have the same breadth as Amazon one day, and if that happens, I'll be happy to use their full-text searches instead. For now, though: does anyone do anything similar to my Amazon searching -- using non-research tools for research/critical writing purposes?