How to remove contextual help on WP 3.3.2?

Since WordPress 3.3, contextual help tabs are added via the Screen object, using add_help_tab(). The basic structure is as follows:

<?php
$screen = get_current_screen();
$screen->add_help_tab( array(
    'id'      => 'sfc-base',
    'title'   => __('Connecting to Facebook', 'sfc'),
    'content' => "HTML for help content",
) );
?>

If you know the $id of a specific help tab, you can remove it using remove_help_tab():

<?php
$screen = get_current_screen();
$screen->remove_help_tab( $id );
?>

If you want to remove all help tabs from the current screen, use remove_help_tabs():

<?php
$screen = get_current_screen();
$screen->remove_help_tabs();
?>

You just need to wrap that in a callback hooked into admin_head, and you’re good to go:

<?php
function wpse50787_remove_contextual_help() {
    $screen = get_current_screen();
    $screen->remove_help_tabs();
}
add_action( 'admin_head', 'wpse50787_remove_contextual_help' );
?>

Some of these functions aren’t well-documented in the Codex yet. Try source directly; they are defined in /wp-admin/includes/screen.php.

Caveat

As-written, these functions will act globally. Most users will want to target a Theme- or Plugin-specific page for doing something like this. If you want to target a specific Theme’s screens, you’ll need to use the Theme-specific hook, e.g.:

<?php
global $wpse50787_options_page;
$wpse50787_options_page = add_theme_page( $args );
?>

Note that, at this point, you can also hook into the load action for your page-specific hook, to execute your contextual help callback:

<?php
global $wpse50787_options_page;
$wpse50787_options_page = add_theme_page( $args );

// Load contextual help
add_action( 'load-' . $wpse50787_options_page, 'wpse50787_remove_contextual_help' );
?>

Then, query for that hook in your callback:

<?php
function wpse50787_remove_contextual_help() {
    // Get Theme-specific page hook
    global $wpse50787_options_page;
    // Get current screen
    $screen = get_current_screen();
    // Determine if we're on our Theme-specific page
    if ( $wpse50787_options_page != $screen->id ) {
        return;
    } else {
        $screen->remove_help_tabs();
    }
}
?>