function modify_user_contact_methods( $user_contact ){
/* Add user contact methods */
$user_contact['skype']= __('Skype Username');
$user_contact['twitter']= __('Twitter Username');
/* Remove user contact methods */
unset($user_contact['aim']);
unset($user_contact['jabber']);
return $user_contact;
}
add_filter('user_contactmethods', 'modify_user_contact_methods');