Akismet checks your comments against the Akismet web service to see if they look like spam or not and lets you review the spam it catches under your blog’s "Comments" admin screen.
Want to show off how much spam Akismet has caught for you? Just put <?php akismet_counter(); ?> in your template.
See also: WP Stats plugin.
PS: You’ll need a WordPress.com API key to use it.
