Check out:
http://www.writely.com/ -- recently acquired by Google.
Nothing to download -- your browser is all you need. With writely, you can:
- Upload Word documents, OpenOffice, RTF, HTML or text
- Create documents from scratch
- Use a simple WYSIWYG editor to format your documents, spell-check them, etc.
- Invite others to share your documents (by eMail address).
- Edit documents online with whomever you choose.
- View your documents' revision history and roll back to any version.
- Publish documents online to the world, or to just whomever you choose.
- Download documents to your desktop as Word, OpenOffice, RTF, PDF, HTML or zip.
- Post your documents to your blog.
- Print your documents