May have discovered an obscure multi-touch gesture
Not sure if this has already been documented, but I think I found a gesture that might be useful. It shows a cover-flow-like array of the icons of recently used documents for certain apps in the Dock.
1. Hover the cursor over an app icon in the Dock.
2. 3-finger swipe downward. The desktop darkens and a row of icons appears.
3. Click on any of the icons to open its associated document.
4. 2-finger left-right swipe to scroll the row of icons back and forth.
5. 3-finger swipe upward to return to the normal desktop view.
This only seems to work for some apps. For example, Text Wrangler and Pixelmator respond to this gesture. But Finder, Mail, Safari, and other built-in apps don't. The 3-finger downward swipe simply shows all their open windows like Exposť did.