There's a new DropBox lookalike launched, cheekily called Copy.
This behaves much like Dropbox, but you get 15Gb free. It is accessible via a browser or a desktop app for Windows, Mac and Linux. It also has iPhone and Android apps. I've been using it for a little while (on Ubuntu & Android) and find it suits my needs pretty well. It creates a folder called Copy in your home folder, and if you save directly to it from AOO your work is automatically synched to the cloud as you write.
For a limited period, if you sign up from my invitation link, you get another 5GB free, giving you a very useful 20GB free storage. Copy Free Cloud Storage
You get the other 5Gb when you install one of the handset apps or the desktop application.