Greg Borenstein writes in about the Quicksilver Radial Menu:

Seeing your screen capture from the Quicksilver preference pane recently reminded me of one of my all-time favorite outside-the-box interface elements: the Quicksilver Radial Menu. I can never quite decide if it’s ingenious or just utterly daft, but it’s a whole alternate interface style available for Quicksilver that opens up a transparent circle around the current item you have selected.

If you invoke it on a folder, for example, the radial menu shows you the contents of the folder arrayed in a circle around that folder’s icon [see below].


Then, if you hold the mouse down on any of the spokes, it shows you the actions available for that item [below].


Also, you can hit the arrow below the central icon at any point to flip the whole works over for more options (for example, to toggle between action and navigation modes). Like everything in Quicksilver, these options are all ingeniously and infuriatingly context-aware, constantly changing based on what kind of item you’ve got and what actions are available.

The whole experience is a little bit like someone smashed open the contents of your hard drive and the capabilities of all of your apps and just laid them open for you on a flat surface.