The picture that appears in user profiles is called a gravatar, which means globally recognized avatar.
Here is how it works: You upload your picture (or your favorite alter ego image) to the website gravatar.com from where we later retrieve your image using a cryptographic key based on your email address.
This way all the websites you trust can show your image next to your posts and your email address remains private.
Please personalize your account with an image - just register at gravatar.com (just please be sure to use the same email address that you used to register with us). The default gray image is generated automatically.