UsageZen: Free Web Part Usage Analyzer Power Tool
Discover usage patterns and reduce license costs by seeing instantly which web parts are in use, how much and where, using the two complementary tools provided by ROXORITY UsageZen:
Usage Analyzer
This command-prompt console application crawls a specified set of site collections, and scans all web part pages (including view and form pages of all lists and document libraries) within all web sites and sub webs underneath those site collections. It produces an XML file recording all individual web part occurences for further processing or analysis.
Usage Browser
This Windows application (screenshot below) reads the XML analysis document produced by the aforementioned Usage Analyzer tool. For each class of web parts, it shows you at a glance how many occurrences were found, and how many of those are "closed" (or "included"), "visible" (or "hidden"), and "minimized" (or "normal"). Once you select a particular web part class, you get to see a complete listing of all occurrences, showing the web part title, title and URL of the container web part page, as well as title and URL of the page's parent web site.