Add custom read more to the_excerpt and

From Twenty Ten’s functions.php:

 /**
 * Returns a "Continue Reading" link for excerpts
 *
 * @since Twenty Ten 1.0
 * @return string "Continue Reading" link
 */
function twentyten_continue_reading_link() {
    return ' <a href="'. get_permalink() . '">' . __( 'Continue reading <span class="meta-nav">&rarr;</span>', 'twentyten' ) . '</a>';
}

/**
 * Replaces "[...]" (appended to automatically generated excerpts) with an ellipsis and twentyten_continue_reading_link().
 *
 * To override this in a child theme, remove the filter and add your own
 * function tied to the excerpt_more filter hook.
 *
 * @since Twenty Ten 1.0
 * @return string An ellipsis
 */
function twentyten_auto_excerpt_more( $more ) {
    return ' &hellip;' . twentyten_continue_reading_link();
}
add_filter( 'excerpt_more', 'twentyten_auto_excerpt_more' );