SketchUp Has Style

Read on http://sketchupdate.blogspot.com/2007/12/make-your-own-custom-styles-with-style.html:

The SketchUp Style Builder is currently in Beta for SketchUp 6 Pro (Win+Mac). It can be found at http://www.sketchup.com/index.php?title=2090 and is free (for now?). It adds a new application alongside SketchUp to thoroughly improve the styles possibilities from SketchUp, which were already impressive.