You can be awarded the following badges for the following reasons:

Kudos King – For having the highest kudos score of the moment

Popular Member – For being mentioned more than 100 times

Supportive Member – For answering more than 60 questions over a 60 day period

Site Enthusiast – For being logged in and active for 30 consecutive days

Awarded Answer – For having your answer awarded

Helpful Member – For answering 20 questions within a 30 day period

Certified Contributor – For answering 100 questions over a 90 day period

Fast Commenter – For replying to a new post within 2 minutes

Newbie Helper – For commenting on a new member first post

Chatterbox – For making at least 100 comments within a week

Influential – For having your post bookmarked at least 25 times