UPDATE: you will require the "all my files" smart search. You have it on your Mac but can download it here: http://1drv.ms/1LjssEt
I wanted a means to open "all my files" when Pixelmator had focus. I couldn't find a way to do this without Finder having focus.
I made this simple workflow to open all my files so I can drag photos into Pixelmator (NB: the workflow is not tied to Pixelmator in anyway).
To activate this workflow you can either type "aa" or invoke it with shortcut "control+command+a"