Worldcat Identities now has subject clouds. These are based on FAST headings in records associated with the identity. Here is the cloud on the page for Conor Cruise O'Brien.

Click on the image to get through to the Identity page. Then click on one of the headings in the cloud to get the top 100 names associated with that heading. And each name will have a similar cloud attached to it.

Here is Thom on the data:

We're still working the bugs out of some of these pages, so they may change over the next few days. We currently have about 1,800 pages for genre clouds (e.g. Love stories) and over a million subject cloud destinations. There is some overlap between the 'subjects' and the 'genres' which we are still trying to understand and rationalize. [Outgoing]