However, the web interface is.  How do I say this.  Rather disappointing.

Take for instance, the Posterous badge in the upper right corner of this page.

Looks innocent, right?  Now, how do you suppose you expand it?  My first thought, click on the arrow of course!

But look what you get.

Logout appears directly under the arrow!  The expansion of the content happens on the hover event, which will right before the click event goes through.  So the end result?

Clicking on the expansion arrow immediately logs you out.

Seriously.  Posterous.  Fix this.

To enable full screen mode, simply have your VM running Ubuntu and click Devices -> Install Guest Additions.

This will mount a disk on your Ubuntu machine.  Simply open the Terminal and run the autorun.sh shell script.

Reboot and your set.  Host + F will now expand your Ubuntu VM to full screen!