It's difficult to say how this utility is needed over, say, judicious use of the native Windows XP or Windows Vista folders for organization and any image editor for resizing. Those that are really into icon creation and modification on a large scale, though, will appreciate a program dedicated to this task.
Extracting icons from another program is a simple matter. I don't like how, after extraction, navigating away from that program also removes all the selected icons from the window. In other words, you can't select a few icons and keep them on the screen while you navigate elsewhere.
IconCool Manager can also connect with any icon editor you choose--not just those made by vendor Newera's IconCool products. That's a nifty feature for those that would rather use an image editor that they're already familiar with.
Note: This is a 30-day demo version. Upgrading provides access to 1300 free sample icons. The vendor did not give details of any other differences.