There is a lot of money to be made with “digg niche clones”. The niche could be regional (country) or topic specific. Both appeal to a specific vertical sector of users.If you are inclined to setup a digg clone, I sugest using either of the free open source solutions in the market – Pligg or Drupal Digg. They are both 100% free. My favorite is pligg, but Drupal is also pretty good and will allow you to add on more community features, should your venture take off and thus you will be able to offer more to your community making your site more sticky. I like pligg because it has an active community for support and they have some nice looking skins. The Admin interface is also very neat with a lot of modules and many plugins and configurable elements. There are countless verticals that you can setup as niche Digg clones. Again make sure you will enjoy running this niche Digg clone before you put in the time and effort to set this up (done in 1 hour max) and then customize it, launch it and market it. Some examples of successful niche market Digg clones are – dubbagol.com, Sphinn, PlugIM, DesignFloat, Dubbagol and Zligg. Dubbagol.com is a regional digg clone and covers all global verticals that digg covers but regional to India – such as bollywood news, India cricket news, desi videos, Indian music, etc.