IconCool Editor 

Powerful icon editor and cursor maker to edit icons, cursors and small web graphics. You can create icons from images of 25 formats or edit icons in exe, dll or icl. Supports 60 image filters, file association, desktop capture, live update and more.
icon editor icon maker icon icons icon creator image editor icon tool edit icon create icon make icon icon library small web image graphics editor image maker

Xentient Thumbnails 

Xentient Thumbnails is a utility for replacing the generic icons of image files with thumbnail icons of the actual image. The utility automatically generates thumbnail icons for most popular image types including JPEG, PNG, GIF, and many others.
desktop icon image thumbnail