How can I quickly check Drupal 7 porting status of the contributed projects? How can I quickly check Drupal 7 porting status of the contributed projects ?

Answers should also guide readers if


a user is a developer and would like to help porting the most
frequently needed Drupal contributed modules, or 
a user is a website owner
and would like to assess a possible upgrade from Drupal 6
to Drupal 7.
There is the Drupal 7 contributed project porting status website that uses data from the Upgrade Status module to show Drupal 7 porting status of the top 61 contributed projects.