WordPress.org

This plugin makes available a number of shortcodes which you can use in your posts, including pagerank and alexa:

• user_count
• post_count
• page_count
• comment_count
• trackback_count
• avg_comments_per_post
• category_count
• tag_count
• link_count
• pagerank
• technorati_authority
• technorati_rank
• alexa_rank
• feedburner_subscribers
• google_backlinks
• yahoo_backlinks
• delicious_bookmarks

The stats are updated daily and then cached.

More info

• Check out Blog Stats for more information.
• Check out my other WordPress plugins.