What are ideal hooks to call register_sidebars?

Question

Where should a plugin ideally hook to call register_sidebar();?

Will init do just fine?

function my_plugin_register_sidebars() {
    $args = array(
        'name' => 'foo'
        'description' => 'bar'
        ...
    );
    register_sidebar( $args );
}
add_action( '**????**', 'my_plugin_register_sidebar' );

Answer 1

Twenty Eleven and Twenty Twelve use the widgets_init action. Given that these themes are generally considered to use best practices for theme development, I think this hook would be ideal.

Answer 2

add_action( 'init', 'my_plugin_register_sidebar' );

Edit: @Brasofilo - the init is used to register menus, I figured it could also be used to register other stuff. I could be wrong though since I don't develop themes. An explanation of why using "init" is wrong would help me in the future. http://codex.wordpress.org/Navigation_Menus