#D7CX: I pledge that this module will have a full Drupal 7 release on the day that Drupal 7 is released.
Update on September 9, 2011: Thrifty 404 has been discontinued now that the Search 404 module includes similar functionality. To see the discussion about it, see .
Update on January 23, 2010: Thrifty 404 is not related to the Fast 404 project. Thrifty 404 is designed to handle missing or relocated content while Fast 404 is designed to handle 404s for arbitrary files (discussed at ).
This utility module replaces the standard "Page not found" page with one that includes a search form populated with search terms taken from the URL. It's designed as a thrifty replacement for the Search 404 module on sites that are experiencing high load from repeated 404 errors (and the expensive search queries that Search 404 automatically runs on each page load).
Naturally, Thrifty 404 requires the core Search module to work. Thrifty 404 is also compatible with the excellent Lucene Search API as long as "Hide core search" is not checked in Administer -> Configuration -> Search Lucene Content -> General settings.