As of recently, there really is no excuse for not adding an XML sitemap to your website. It may have been a bit complex at first, but programs like SiteMap Builder make it really easy to do.
Submitting a sitemap for a Blogger blog
( ie. yourblog.blogger.com), or other blogs not hosted by you (where you don’t have access to the root directory).
According to Google, you can submit some RSS feeds.
Google accepts RSS 2.0 and Atom 0.3 feeds that use the and modified date fields. If you use a syndication feed in one of these formats for your site, you can submit the URL of the feed to let Google know about recent changes to your site. Google uses the field in your feed to gather URLs from your site and uses the modified date field (the
field for RSS feeds and the date for Atom feeds) to learn when each URL was last modified. Use of the modified date field is optional. Make sure that the feed is located in the highest-level directory you want search engines to crawl.
Generally, a syndication feed does not include all URLs, so if you want to use the feed to let Google know about all URLs in your site, you may need to adjust your feed settings. If your feed includes only recent URLs, Google can still use that information to find out about other pages on your site during its normal crawling process by following links inside pages in the feed. If you use this format for your site, simply submit the URL of the file.