The title says it all. If you use the Gimp and are into serious Second Life photography, visit the WU-Gallery blog for more information on these plugins.
The LoopTools add-on is a powerful script containing a collection of tools to aid mesh modelling in Blender 2.5. Click the link for further information on where to download the addon.
Artisan is a plugin for SketchUp, an organic toolset that works pretty much like the terraforming tool in Second Life. It’s a commercial product, price is US$39.00.
Quoting from the web site:
Artisan is a set of powerful organic modeling tools. It builds upon the subdivision tools in Dale’s previous plugin, Subdivide and Smooth, and adds new tools to SketchUp that provide unprecedented control over complex high-poly forms.
While subdivision modeling is the core of the plugin, the sculpting and soft transformation tools allow you to take your models even further. Artisan gives you the power to model things that were previously not possible in SketchUp.
A commercial Photoshop plugin with some cool effects. Click the link for more information.