Enter Akismet key for each site? Really?

+1 to this.

I would love for someone to post a solution or perhaps have this included as a(n optional) feature for a future WP update.

Look at the top of the source code for akismet.php in the plugin, it mentions how to hard code a key for the entire site.

Awesome – thanks Joseph

Add a line like this to your wp-config.php file:

define('WPCOM_API_KEY','your-key');

This will work with Akismet, the Stats plugin, etc.

Correct, which is what the akismet.php code mentions:

/** If you hardcode a WP.com API key here, all key config screens will be hidden
 */
if ( defined('WPCOM_API_KEY') )
    $wpcom_api_key = constant('WPCOM_API_KEY');
else
    $wpcom_api_key = '';

Do realize that if you use the Akismet plugin sitewide, you may come under their Commerical Usage clause:

https://akismet.com/commercial/

Discussed here as well:

https://mu.www.ads-software.com/forums/topic/16257

@tdjcbe: Thanks for the warning. Luckily, none of my sites fall under the statement below (found at the personal page of Akismet).

If you are a commercial entity or if you are making more than $500 from your personal blog, please get a commercial key instead.