Just saw this in a Tips thread on the Retouching Forum:

This is to enhance the colors of the image especially taken with low to mid end digital cameras, generally suffering from poor color saturation.

Typical adj. layer with hue/saturation would result in ugly artifacts. This method might be a better alternative.

Duplicate background>select the copy>image> adjustment> hue and saturation> increase the saturation to around 60-70 (image will look to be absolutely trashy)>go to filter>noise> median(select around 6 )>filter>blur> gausssian blur(select around 4)>set the blend mode to color>dial the opacity as per the liking.

Enriches the colors in otherwise bland images without the accompanying artifacts.