Windows only: Like the look of BumpTop but not part of the invite-only beta? Free application Shock Desktop 3D is a lightweight BumpTop alternative that turns your Windows desktop into a 3D environment where you can interact with your documents in a physical space. The video above—put together by reader y0himba<—demonstrates some of Shock Desktop 3D's interface in action. If you like the look of BumpTop, Shock Desktop 3D looks like a nice alternative. With either option you'll need a decent video card and be willing to sacrifice a little memory (Shock Desktop 3D eats about 35MB on my system), but if the 3D desktop seems more intuitive to you (or you just want to have a little weekend fun), it might be worth a try. Thanks y0himba!