I came across this simple piece of software on the Mori forums. Think lets you focus a selected application, and place a background colour between it and the other programs you are running. In essence, it is a bit like “full screen” for your entire application. The interface is very simple, composed of a slider for the opacity of the background, a colour selector (default black), and a button to select a focussed application.
You might have come across other utilities which block out everything except for the application you are working on, but Think takes the concept a step further. It acknowledges that you sometimes need more than one application focussed. Using the dock or your favourite application switcher (such as Cmd-Tab), you can promote other applications to visibility. However, it still retains the original selection as the focussed application (indicated by the icon of the chosen program in a “thinking bubble” in the dock). This means that, while you can have multiple programs “above the fold,” returning to your focussed environment is dead simple. Simple click anywhere on the background, and all of the alternate programs drop back below the background, leaving just the chosen focussed application. Brilliant, interface-less execution at its best.
Choosing a new application to focus is likewise very simple. You can either click on the necessary icon in the control strip, or Think’s dock icon. You will be presented with the icons of all running applications in a manner quite like Apple’s task switcher. My only grief with this process is that you must use the mouse to select the focussed application.
If you wish to temporarily disable Think’s focussing powers, simply hiding the application will do the trick.
There are still some bugs, in my opinion. Think’s background layer comes up as a window in Expose; switching back to Think after hiding it produces an blank screen you have to click on once to re-focus your selected application; and integration with Finder/Path Finder is perhaps not as well thought out as it could be. The desktop is an important part of the file management system on a Mac, yet Think blocks the desktop in both of these applications. I understand there are technical reasons for that, however, as it would have to hide all of your applications to reveal the desktop. Otherwise, it is a very solid 1.0.
Think is freeware, and available at this location.