Sorry for digging this up, but here is an small example of what nice sharpen can do the scene (it is of course photoshoped ). I used smart sharpen.
The diffrence is probably exaggerated by the quality of screenshots, but it should give overall nice idea of how it can be used to add realizm and/or sylize image a bit.
Original Image:
https://dl.dropboxusercontent.com/u/70400220/November2013Noob/ScreenShot00023nosharpen.png
Smart Sharpen Filter:
https://dl.dropboxusercontent.com/u/70400220/November2013Noob/ScreenShot00023.png