There is a newer version of this plugin available at Sketchup's own website.
Before and after using the Texture Depatternizer. The textures of each segment of the barrel where identical since they are all rotated copies. In this example the script has been used in the middle of each segment and the texture position of the sides has been manually adapted to it.
Here the Texture Aligner and Texture Rotater have been used. The textures of the 3rd, 6th and 7th step are identically positioned, as well as the others. This is easily fixed with the plugin. Just select faces and click at the toolbar.
Texture depatternizer
Sometimes when copying faces or using my Texture Aligner strange patterns appears between the faces as a result of their textures being aligned identically. The solution is this script that randomly moves textures while preserving rotation and scale.
Depatternize
Randomly moves around textures on all selected faces to get rid of patterns they form.
At the time these tools only affects the front side of the faces.
Download script
Installation: Unzip all files and folders to the plugin folder.
Example of models
Castle