Seems to be a popular question, and haven't made it clear in the readme file, so here's the trick.
1. Sign up for a Gravatar for your e-mail address on gravatar.com
2. Login to your WordPress admin, browse to Settings - General
3. Set the Admin E-mail to the e-mail address you registered with on Gravatar.com.
New Gravatars might take a while to appear, so hang in there, and don't hesitate to ping me if you need any help!