Issuu : Online PDF Viewer
Issuu describes itself as “free online publishing service and a creative community dedicated to publishing”. In simpler terms, it’s a document sharing community with a focus on creatives. The best thing about it, is its web-based PDF viewer that makes online document viewing/reading much more interactive. Photographers can use it to show off their portfolios, regular folks for more interactive eBook reading experience and so on.
Features
- View and navigate PDF documents using interactive PDF viewer.
- Embed docs onto your website, Facebook account, Myspace, Orkut, Blogger, Friendster, Typepad, LiveJournal, etc.
- Facebook application: Add Issuu document viewer to Facebook profile.
- Customize viewer: Choose background theme, width, background color etc.
- Document restrictions: Should be smaller than 100 MB and less than 500 pages.
- Browse documents shared by others, bookmark to favorites, leave comments, etc.
Check out Issuu @ www.issuu.com
We have posted one of our four color how-to books to issuu, we really like the format. Our Yoga book is located here: http://www.maran.com/onlineyoga.html
I prefer Samuraj Data when I’m in rush to view a PDF from a URL and not local file. An advanced version is PDFEscape.com with more features. But the output is an image which means links are not click-able.
For click-able links I think PDFMeNot.com is currently the best out there. 
I dislike it because it requires Flash – but the links are click-able because of Flash technology I guess… ? 