Dropbox (store, sync, and share files online)

Dropbox is an extension that integrates the Dropbox web service with 
your desktop.  It consists of two major components: dropboxd - a per
user closed-source daemon process that makes sure your $HOME/Dropbox 
directory is properly synchronized with the web Dropbox server/service,
and dropbox-client, which connects to your dropboxd and presents a GUI 
based on the information dropboxd provides.