Edward R. Jenkins

Adds new user profile fields, including Facebook, Twitter, Google+, Deviant Art and Tumblr. These new fields can be used in your template with get_author_meta(”)
For example, to add the Google+ URL you would use get_author_meta(‘googleplus’).

Better User Profile Fields

Simple plugin that adds new user profile fields, including Facebook, Twitter, Google+, Deviant Art and Tumblr.

Christiaan Conover

Author Customization gives you much more flexibility in managing post and page author data. Your author data will no longer be tied solely to the WordPress user system, and can now be managed on a per-post basis. Author name and description are saved with each post, allowing you to preserve this information as it was when the post was published.
Features
<ul>
<li>Per-post author display name and biographical info</li>
<li>TinyMCE (WYSIWYG) editor for user profile and per-post biographical info</li>
<li>rel=”nofollow” link inside biographical info entries</li>
</ul>

Author Customization

Author Customization expands core author management with features such as per-post author information and rich user bio editing.

Better User Profile Fields vs Author Customization