profile.php

<?php

/**
 * Add more profile fields to the user
 *
 * Easy to add new fields to the user profile by just
 * creating your new section below and adding a new
 * update_usermeta line
 *
 * @since 3.0.0
 * @uses show_user_profile & edit_user_profile WordPress functions
 *
 * @param int $user User Object
 * @return bool True on successful update, false on failure.
 *
 */
function cp_profile_fields($user) {
?>


    <table class="form-table">

        <tr>
            <th><label for="twitter"><?php _e('Twitter','cp')?></label></th>

            <td>
                <input type="text" name="twitter_id" id="twitter_id" value="<?php echo esc_attr(get_the_author_meta('twitter_id', $user->ID)); ?>" class="regular-text" size="35" /><br />
                <span class="description"><?php _e('Please enter your Twitter username.','cp')?></span>
            </td>
        </tr>

        <tr>
            <th><label for="facebook"><?php _e('Facebook','cp')?></label></th>

            <td>
                <input type="text" name="facebook_id" id="facebook_id" value="<?php echo esc_attr(get_the_author_meta('facebook_id', $user->ID)); ?>" class="regular-text" /><br />
                <span class="description"><?php _e('Please enter your Facebook username.','cp')?></span>
            </td>
        </tr>

    </table>


    <table class="form-table">

        <tr>
            <th><label for="paypal"><?php _e('PayPal Email','cp')?></label></th>

            <td>
                <input type="text" name="paypal_email" id="paypal_email" value="<?php echo esc_attr(get_the_author_meta('paypal_email', $user->ID)); ?>" class="regular-text" /><br />
                <span class="description"><?php _e('Please enter your PayPal email address.','cp')?></span>
            </td>
        </tr>

    </table>

<?php
}


function cp_profile_fields_save($user_id) {
    if (!current_user_can('edit_user', $user_id ))
        return false;

    /* Copy and paste this line for additional fields. Make sure to change 'twitter' to the field ID. */
    update_usermeta( $user_id, 'twitter_id', $_POST['twitter_id'] );
    update_usermeta( $user_id, 'facebook_id', $_POST['facebook_id'] );
    update_usermeta( $user_id, 'paypal_email', $_POST['paypal_email'] );
}


// hook these new fields into the profile page with high priority
add_action('show_user_profile', 'cp_profile_fields', 0);
add_action('edit_user_profile', 'cp_profile_fields');

// save the updated profile field information
add_action('personal_options_update', 'cp_profile_fields_save');
add_action('edit_user_profile_update', 'cp_profile_fields_save');

?>