I initially used FamFam Silk Icons for the File Browser, but had to later switch to GPL licensed icons due to incompatibility of Fam Fam Creative Commons Attribution 3.0 license with Drupal's requirement of GPL 2 license.
So, I decided to create icon sets for the File Browser independently, and upload them here. Currently, you would find 2 icon sets, the default shipped with the folder, and the Fam Fam icons that I originally used. Over time, I might add more icon sets depending upon the free time I get to devote to this module.
Using an alternative icon set is as easy as extracting the appropriate set's zip in the module's images folder (normally located at /sites/all/modules/take_control in your Drupal root folder), overwriting the existing icons.
You can as easily use your custom icons, by naming them appropriately and uploading to the images folder inside the module folder. The icon names are sufficiently self explanatory, to be able for you to figure out.
For general discussion on the module not related to the icon-sets, please use the comment form on the permanent page for this module here.