public function save() {
		global $wpdb;

		/**
		 * Filters the blog user ID before save.
		 *
		 * @since 1.0.0
		 *
		 * @param int $value User ID.
		 * @param int $value Site ID.
		 */
		$this->user_id = apply_filters( 'bp_blogs_blog_user_id_before_save', $this->user_id, $this->id );

		/**
		 * Filters the blog blog ID before save.
		 *
		 * @since 1.0.0
		 *
		 * @param int $value Blog ID.
		 * @param int $value Site ID.
		 */
		$this->blog_id = apply_filters( 'bp_blogs_blog_id_before_save', $this->blog_id, $this->id );

		/**
		 * Fires before the current blog item gets saved.
		 *
		 * Please use this hook to filter the properties above. Each part will be passed in.
		 *
		 * @since 1.0.0
		 *
		 * @param BP_Blogs_Blog $this Current instance of the blog item being saved. Passed by reference.
		 */
		do_action_ref_array( 'bp_blogs_blog_before_save', array( &$this ) );

		// Don't try and save if there is no user ID or blog ID set.
		if ( !$this->user_id || !$this->blog_id )
			return false;

		// Don't save if this blog has already been recorded for the user.
		if ( !$this->id && $this->exists() )
			return false;

		$bp = buddypress();

		if ( $this->id ) {
			// Update.
			$sql = $wpdb->prepare( "UPDATE {$bp->blogs->table_name} SET user_id = %d, blog_id = %d WHERE id = %d", $this->user_id, $this->blog_id, $this->id );
		} else {
			// Save.
			$sql = $wpdb->prepare( "INSERT INTO {$bp->blogs->table_name} ( user_id, blog_id ) VALUES ( %d, %d )", $this->user_id, $this->blog_id );
		}

		if ( !$wpdb->query($sql) )
			return false;

		/**
		 * Fires after the current blog item gets saved.
		 *
		 * Please use this hook to filter the properties above. Each part will be passed in.
		 *
		 * @since 1.0.0
		 *
		 * @param BP_Blogs_Blog $this Current instance of the blog item being saved. Passed by reference.
		 */
		do_action_ref_array( 'bp_blogs_blog_after_save', array( &$this ) );

		if ( $this->id )
			return $this->id;
		else
			return $wpdb->insert_id;
	}