There is a lot that you can do in Adobe Camera Raw from sharpening to color fringe correction to lens correction to color correction to Black and White conversion. Adobe Camera Raw is a powerful tool and working on files that are raw will give you the most creative results. Of course there is the Clarity adjustment in ACR that is a non invasive way of sharpening. Camera raw is a powerful and useful tool that has been improved in CS6 and is very effective in CS5. When I process my images in ACR I have little to do in Photoshop because my files are pre worked in ACR. Of course it is very easy to over do things and especially sharpening can be easily over done. I have my own technique for final sharpening that is non invasive and very effective.