Module Link: http://drupal.org/project/Radioactivity

The Radioactivity module allows you to give energy (popularity) to your content through a variety of methods and then has the energy bleed off at a specified rate. Think Digg front page.

• Who: Technical and non-technical users. Non-technical users, be careful with the settings of this module.
• When: I use this when I'm going to have user controlled popularity sorting on content.
• Where: You can find the settings for this module at /admin/settings/radioactivity. If you are planning to use the memcache functionality make sure to install the memcache module and configure it properly for the Radioactivity module to pick it up.
• Why: It's a great system to allow users to promote content but it allows the promoted content to fade out gracefully.

Theme song "i dunno" by grapes.