SharePoint Web Parts Not Exposed in the UI by Default

Every time I get to the point that I think I’ve got a reasonable handle on what is available within SharePoint, someone points out something I didn’t know.  SharePoint (whether you are referring to WSS or MOSS) is just a really large beastie, and there’s a lot to it.
The other day, a new colleague of mine, Bob Nash from CSC, showed me that there is a large set of Web Parts available in a MOSS installation that is not exposed through the UI by default.  If you go to the root of the Site Collection, Site Action/Site Settings, and go into the Web Parts Gallery, you will see all of the Web Parts that are currently available to the end user.  By clicking on the New toolbar button, you can see all of the Web Parts that are available within the Site Collection.  Some of these are not exposed by default; for instance, Microsoft.SharePoint.Portal.WebControls.QuickLinksMicroView is the Web Part that is on the My Sites page that allows the user to create their own set of links.  By selecting that Web Part and clicking on the Populate Gallery button, it will be available for use in the Site Collection and not just in the My Site context.
Take a look through what’s available here, as some of it is really handy stuff. 

Have a thought or opinion?