Here is a good video from Marketingprofs on youtube explaining Digg. Notice the little icons below blog posts sometimes that say Digg this? The following is what the process is and another example of how the net continues to evolve.

Share and Enjoy: These icons link to social bookmarking sites where readers can share and discover new web pages.
  • Digg
  • del.icio.us
  • Netvouz
  • Technorati
  • DZone
  • StumbleUpon
  • Furl
  • Wists
  • Spurl