I finally put up some documents on Scribd, Docstoc, and Slideshare. I've been taking embeds from other documents on these sites, but never contributed to them.
Since I get various requests for sample business plans and investor presentations, I decided to put up some old documents so that other entrepreneurs can use them as a template or just to gain some ideas as they create their own.
As for my thoughts on each of these services...
I give them a thumbs up. They had the most features and best controls. For example, I liked that you could decide whether people could download the original word doc, a PDF version, or both. The vast majority of their site are word documents, manuscripts and the like. Books, catalogs, legal documents, resumes, sheet music, etc. They truly are a document repository for everyone's fancy.
I give them a thumbs down. They position themselves as a place for professional documents with a good mix of word docs and slides. What I didn't like was that there weren't any controls for blocking downloads on public documents, which the other two provided. Also there weren't controls for the type of document you could download, and my GoingOn slides did not upload cleanly. The background color was changed for the worse.
I give them a thumbs up. They focus on slides and do it well. They have the download or not download option for your uploaded documents, but don't have the PDF option.
Anyway, here are a couple of my old pitches on Slideshare: