Is there a way I can change and set a default avatar for signing up instead of the smiley. Example: If a female signs up a default picture that I have for a girl will be the avatar until she changes it. If a male signs up a default picture of a man avatar will be displayed.

OR....

Can I list small images during sign up say 5 for example have the small image shown to the user and require them to select one of the images to sign up. The would be selected via a radio button with the small image of the avatar shown above. Once the user selects the chosen avatar and fills in the remaining info for the signup page correctly and clicks submit that will be their default chosen avatar.