I was just idly mousing over folders in Nautilus on my laptop, when all of a sudden these window-dragging icons appeared and I was moving my window across the screen. Look at the screenshot to see what I mean.

What was that, and how do I turn it on again? Because that looked really cool. I tried, but couldn't get it to display again.

This is an unmodified Ubuntu 11.10 upgraded from Ubuntu 11.04, on a Toshiba Satellite A505. I was using the touchpad.