wp-get_all_blog_ids

<?php 
/**
	 * Get all blog ids of blogs in the current network that are:
	 * - not archived
	 * - not spam
	 * - not deleted
	 *
	 *
	 * @return	array|false	The blog ids, false if no matches.
	 */
	private static function get_blog_ids() {
		global $wpdb;

		// get an array of blog ids
		$sql = "SELECT blog_id FROM $wpdb->blogs
			WHERE archived = '0' AND spam = '0'
			AND deleted = '0'";
		return $wpdb->get_col( $sql );
	}