New2WP Author Box
What this plugin does is utilize the WordPress dashboard profile section, which is so very neglected to my knowledge. It will replace the Yahoo IM field that most people may find rather useless, with a Twitter field.
Authors can then add their Twitter name, if they choose, and using the other existing fields they can add their URL to their website, with a little blurb about themselves in the biographical info box, and obviously their email address. It’s very basic, but does the job for most multi-author sites.