Cairo Dock 2.3 (currently in beta) got a cool new feature that lets you easily browse recent files such as documents, audio and video files, websites and so on thanks to Zeitgeist. The new applet also has a search and looks a lot like Sezen.
Fabounet, one of the Cairo Dock developers recorded a video with the new Zeitgeist applet in action:
If you want to try it out, you'll find installation instructions HERE (but remember it's still in beta so not everything may work). Once you've installed everything, add the "Recent Events" applet to Cairo Dock.