There is a function exactly for that:
get_page_by_title( $page_title, $output = OBJECT, $post_type="page" );
You can use it like this:
$page = get_page_by_title( 'Start' );
To get the page from a specific post type:
$custom = get_page_by_title( 'Start', OBJECT, 'your_custom_post_type' );
$post = get_page_by_title( 'Start', OBJECT, 'post' );
Be aware, this function will search in all post statuses. So you might get a draft, a trashed or private post. You should check the result with:
$status = get_post_status( $page );
if ( 'publish' !== $status )
return; // do not show unpublished posts
A related function is get_page_by_path()
:
$page = get_page_by_path( 'about/contact' );