SuperSite for Windows discovered a secret feature in the beta version of Windows 7 called Aero Shake. Paul Thurrott explains you can maximize windows by shaking with your mouse after you've click and hold on the grabbable area of any floating window:
Aero Shake is as easy to describe as it is difficult to discover: Simply click and hold on the grabbable area of any floating (non-maximized) window and shake your hand left and right vigorously. (This works much better with a true, external mouse than it does with a trackpad, thumb nub, or other pointing device, in my experience.)
When you do so the first time, all other open windows are minimized. Repeat the action, and those minimized windows will be restored to their prior state.
Aero Shake is designed as an adjunct to Aero Peek, though it works a bit differently. In this case, the focus is on the selected window, as you'd expect. And other windows are truly minimized: That is, they disappear from the screen entirely and you don't see a "ghost window outline" as you do with Aero Peek.