A popular feature request for sites that deal with a lot of content, is to see for each page what other pages are linking back to it. This can be helpful when doing some SEO or cleaning up and rewriting old content.
In Drupal 7 this is easily done. It exists where you wouldn't immediately expect it though: the core search module. Kind of mimicking how search bots like Google's indexer works, Drupal 7's search module now takes the amount of nodes linking back to another node to calculate the score for some result.



