Crocodoc

Crocodoc lets you quickly upload any document (PDFs, Word documents, and PowerPoint presentations,etc.) and turn it into a webpage, and lets you view and mark them up online.
This is an extraordinary tool. Students can create anything, for example, using Microsoft Word, and immediately turn it into a webpage. This is an extraordinary way for people who are not familiar with creating online content to use a program that they’re familiar with — like Word — and develop something very useful that can be shared with everybody.
You do have to register to use it, but it is a free service for most of it's features.