UPDATE 30/07/2012,a client developed by insync was released few days a go, wonderful 😉
Wtih Grive you can easily download your Google Docs/Drive to your computer.
To install it in Ubuntu just follow this instructions.
To automate the sync of your files, just create a file in your /home/ folder called googlesync.sh and paste this code:
#!/bin/sh
SERVICE='grive'
if ps ax | grep -v grep | grep $SERVICE > /dev/null
then
echo "$SERVICE already running, skipping sync."
else
cd ~/grive
grive
fi
Later edit your crontab (crontab -e) and add this line, so you folder will synchronize every 10 minutes:
*/10 * * * * /home/YOURUSER/googlesync.sh