We are working on the "pivots" project as an attempt to give module recommendations. The idea is to display on a module page the related forum conversations and related modules that are referenced in the same conversations. We think it could provide some useful information for users to decide whether to download a module or how to use it.

The "pivots" system has been enabled for D.O. site maintainers and CVS account holders. More details can be found here: http://drupal.org/node/265450

We are about to deliver it to all interested D.O. users. And we hope to get some code reviews from the community to improve code quality.

The code is published to CVS: contributions/modules/pivots4do

Or, for a quick browse, you might go to the following links.
PHP:
http://danithaca.pastebin.com/m798c291d
http://danithaca.pastebin.com/m2ea9911a
Java Indexer:
http://danithaca.pastebin.com/m1b147b25
http://danithaca.pastebin.com/m53f9621b
http://danithaca.pastebin.com/m592c46ec

For a short description of the architecture and security concerns, please refer to:
http://drupal.org/node/265450#comment-884264

Your comments would be much appreciated. Thanks!