Apparently the web world is fed up with PDFs, because alternatives are popping up left and right.
The latest entry into this world is iPaper, which aims to entirely replace the PDF.
The basic idea is that, like a YouTube video, iPaper documents can be embedded into any existing web page through a Flash widget, and can display PDF, Word, PowerPoint, Excel, and other document formats without the need for separate readers.
Features include viewing documents without downloading any additional software, monetizing documents with integrated advertisements, social aspects with a built in share functionality, enhanced security, and easy integration.
Edit: Box.net, a free online storage and file sharing site, is one of the first sites to embrace the iPaper technology. You can now view any of your PDF, Word, Excel, or Power Point documents that you have stored on Box.net using iPaper.