This is cool, I've been doing something similar w/ the combination of the google command line tools and Mac's folder actions. Although it is only one way.
Basically you designate a folder to always upload to google docs, then when you add a file you have the folder action run the google command line tool to upload the file.
Basically you designate a folder to always upload to google docs, then when you add a file you have the folder action run the google command line tool to upload the file.