Installation and Using:

mkdir -p ~/bin
wget -O ~/bin/dropbox.py "https://www.dropbox.com/download?dl=packages/dropbox.py"
chmod +x ~/bin/dropbox.py

Using:

 
 ~/bin/dropbox.py help

Source: http://www.dropboxwiki.com/tips-and-tricks/using-the-official-dropbox-command-line-interface-cli