WPMU flush rewrites

<?php
private function set_rewrite_rules(){
$default_structure = '/%category%/%postname%/';
if(!get_option('aio_initialized')){
global $wp_rewrite;
$wp_rewrite->set_permalink_structure($default_structure);
$wp_rewrite->flush_rules();
update_option('aio_initialized',1);
}
}
?>

Save plugin options multisite 3.1

<?php
//Snippet1 - New action for creating your buddypress submenu pages - replace 'create_my_submenu_page' with the name of your function

add_action(is_multisite() ? 'network_admin_menu' : 'admin_menu','create_my_submenu_page');

//Snippet2 - This is the form for submitting your plugin options. This works for plugins that only function on the main site, to account for plugins that are used on the network you may want to replace the update_options() with update_site_options() and check ahead of time to decide which to use.

<?php

function my_plugin_admin_form(){
if(isset($_POST['my_submit'])){
if(!isset($_POST['my_option']['my_display_tool'])) $_POST['my_option']['my_display_tool'] = 'false';//If no checked box in post set value to false

foreach((array)$_POST['my_option'] as $key => $value){//Add more my_option[FIELDNAME] to form for more fields
update_option($key,$value);
}
}
$my_display_tool = get_option('my_display_tool');
?>

<div class="wrap">
<h2>My Settings</h2>
<?php if(isset($_POST['my_submit'])) : ?>
<div id="message" class="updated fade">
<p>
<?php _e( 'Settings Saved', 'my' ) ?>
</p>
</div>
<?php endif; ?>
<form method="post" action="">
<?php settings_fields('my_settings'); ?>
<p style="margin-bottom:30px;">
<label style="display:block;" class="input_label">ON/OFF Switch:</label>
<br />
<input name="my_option[my_display_tool]" type="checkbox" <?php if($my_display_tool == 'true') echo 'checked'; ?> value="true" />
<!-- Add more my_option[FIELDNAME] to form for more fields -->
<span class="checkbox_text">Turn This On</span><br />
</p>
<p>
<input name="my_submit" type="submit" class="button-primary" value="<?php _e('Save Changes') ?>" />
</p>
</form>
</div><!-- /.wrap -->
<?
}
?>

BP fix for WP 3.1

add_action( is_multisite() ? 'network_admin_menu' : 'admin_menu', 'MYCALLBACKFUNCTION' ); //Replace callback with the name of your function that adds the submenu page.

Thickbox path fix for enqueue

<?php
function wpvp_enqueue_js(){
?>
<script type="text/javascript">
var tb_pathToImage = '<?php echo bloginfo('wpurl') ?>/wp-includes/js/thickbox/loadingAnimation.gif';
var tb_closeImage = '<?php echo bloginfo('wpurl') ?>/wp-includes/js/thickbox/tb-close.png';
</script>
<?php
wp_enqueue_style('thickbox');
wp_enqueue_script('thickbox');
}

add_action('wp_print_scripts', 'wpvp_enqueue_js');

?>