SpiderOak provides an easy, secure and consolidated free online backup, sync, sharing, access & storage solution for Windows, Mac OS X, and Linux (Ubuntu, Debian & Fedora)
Adobe Share allows you to share, publish and organize your documents, e.g. embed a Flash preview of your document on any website. OK, it's a beta, doesn't seem to work for me.
Clipperz is a free and anonymous online password manager. Local encryption within the browser guarantees that no one except you can read your data. Nothing to install.
Omnidrive is what you expect hosted storage to be - easy to use, accessible from anywhere and unrestrictive. Omnidrive will make your life easier by allowing you to store, access and stream your files from almost any web connected platform.