I'm looking for a way to create a "Related Content" type of block, which will recommend similar content to my readers when they're viewing a node.

ApacheSolr has a similar project as well, which is/will be used to replace the old "pivot" module.

More information about this module here:
http://drupal.org/project/apachesolr_autotrack

If there's already a way to do this, could someone please enlighten me.

Thanks,
JOrdans