If you want to show your sites contributor information then this plugin for you. It’s nice graphical user interface will guide you to show their avater, email address, position and twitter handler with few clicks. From the widget page in wp-admin you can handle this.
How to configure SpokesPersons?
First you need to install it from your plugin installation page or you can download it and upload it from there too. SpokesPerson need two more information then the WordPress have, your position and twitter handler. In every user profile page you find two extra (after activating) field like below.
Every user can fill those information with their own. Now go to your widget page from wp-admin, find the widget and place it to a widget area. This should look like below.
In this screen you will see all existing users of your site. You can simply check as many as you want to show in widget and save it. It will look like below.