A Nautilus Python extension adding a entry in the right click menu to open the Guake terminal in the current directory.
When clicked, Guake get the focus, creates a new tab and set the current directory to the directory you where in Nautilus.
The master branch is for nautilus 3. There is another branch for nautilus 2.
GPL2 licence. Enjoy.
The easiest way is to install Nautilus PyExtensions that will let you handle that with a nice GUI. Plus you'll get other extensions as a bonus.
Don't forget to restart Nautilus once you added the extension.