What do you think of using XML sitemaps?
 

An XML sitemap:
- Ensures better visibility by search engines
- Enables you to rely less on external links that will bring search engines to your site.
- Helps with broken internal links or orphaned pages that cannot be reached in other way
- Alerts search engines to any changes/additions to your site
- Helps you choose pages that you don�t want to index
What do you think about it?

I think using a sitemap is essential from a "best practices" standpoint. It's just one thing among many others that search engines look for. If you have a Wordpress site, then there are several good plugins that can handle this automatically.