How to add a Recent Items stack to the Dock on Mac OS X
Mac OS X stacks usually list the contents of specified folders, but the Dock has a hidden Recent Items Stack feature for Applications, Documents, Servers, and Volumes.
To enable the Recent Items Stack, open a new Terminal window and enter the command below:
defaults write com.apple.dock persistent-others -array-add '{ "tile-data" = { "list-type" = 1; }; "tile-type" = "recents-tile"; }'
... then right-click on the new Stack to choose which information to display.
To revert the change, right-click (or control-click) on the Recent Items Stack and choose the "Remove from Dock" option.