I recently discovered Scribd as a high-profile source of books and documents put out in the public domain. It is a really interesting website, and it prompted me to publish an outline and extract of my novel Sandman there. I would suggest other authors do not miss out on this site, given its really high Alexa Ranking: meaning it will gain lots of 'eyeballs'! However, if you just want to get to an extract of 'Sandman' fast, I would suggest you go straight to Sandman on my own website for an easier form.
Gaining online presence is a never-ending task for authors these days and so knowledge of high profile platforms is valuable information. Publishing a reasonable extract from your book makes a lot of sense. I hope this information aids fellow authors to find a great place to do just that.