Fenric has been very busy lately and has managed to make three new plugins for Carrara and even a new store to buy them from at a very low price. There are also trial versions available. Here is the basic info about them, more data available at Fenrics site:
Layer Blending Mode Shader
This is a Carrara shader that provides Photoshop-like layer blending.
Enhanced Color Shaders
These are enhanced versions of the Color Balance and Color Merge shaders from the “Pose and Shading Tools 2″ package at DAZ. They take a sub-shader for control rather than using sliders.
Selection Changer
Change the current selection using your keyboard!
More info and how to buy the plugins here: http://fenric.com/wordpress/store/products/category/carrara-plugins/Trials here: http://fenric.com/wordpress/downloads/