From a post by David Blei:
allison chaney has created the “topic model visualization engine,” which can be used to create browsers of document collections based on a topic model. i think this will become a very useful tool for us. the code is on google code:
http://code.google.com/p/tmve/
as an example, here is a browser built from a 50-topic model fit to 100K articles from wikipedia:
http://www.sccs.swarthmore.edu/users/08/ajb/tmve/wiki100k/browse/topic-list.html
allison describes how she built the browser in the README for her code:
http://code.google.com/p/tmve/wiki/TMVE01
finally, to check out the code and build your own browser, see here:
http://code.google.com/p/tmve/source/checkout
Take a look.
As I have mentioned before, LDA could be a good exploration tool for document collections, preparatory to building a topic map.