For a project I needed the faceted_search module and that project was screaming for being made in Drupal 6. Since there isn't a drupal 6 version of this module, I decided to just port it myself.
The patch isn't complete yet. I just ported the things we needed directly. When I have some spare time, I will continue the port.
Faceted Search Views and Field Keyword Filter are untested, but the views will not work for sure, since it's not updated yet for views 2.