It annoys me that drupal display anonymous as commentor's name and no persoanl info is required. I spent some time on hacking this up, here is how:

• Go to the content type you desire to enable comments, locate comment settings and choose " Anonymous posters must leave their contact information". This will translate the comment form into a full-blown form with "Your name", "E-mail", "homepage" and
  "comment". Nice! However, your name still uses anonymous. Our goal is to get rid of it.
  
• Piece of cake with jQuery. shuvuu posted a nice solution on http://drupal.org/node/240610, basically apply the following code which finds the edit-name then clear its value.
  

  Inject the above code into page.tpl.php, you are all set.