amemiku

The SEO Slugs 4 bbPress plugin removes common words like ‘a’, ‘the’, ‘in’ from post slugs to improve search engine optimization.
For example, when you publish a post with a title like this:
“What You Can Do Immediately For Higher Rankings”,
WordPress automatically assigns a long filename to your post, called a post slug:
/what-you-can-do-immediately-for-higher-rankings
SEO Slugs 4 bbPress plugin strips common words like “what”, “you” or “can” out of your post slug to make it more search engine friendly. With SEO Slugs plugin activated, the slug for our example blog post would look like this:
/immediately-higher-rankings
The slug is generated on saving a post (so you get a chance to look at it before publishing, and change it), or on publish. It won’t overwrite an existing slug. You can force a new slug generation by deleting the existing one.

SEO Slugs 4 bbPress

Removes common words like 'a', 'the', 'in' from post slugs to improve SEO.

microkid

This plugin gives you full control over the permalinks for author pages. When using “pretty permalinks”, by default URLs to author pages are structured:
http://www.example.com/author/author-name/
With this plugin you can change the “author” part of these URLs into anything you like, for example:
http://www.example.com/editorial/author-name/ 
http://www.example.com/crew/author-name/ 
http://www.example.com/members/author-name/ 
http://www.example.com/posts-by/author-name/
The plugin will also automatically change links throughout your site that point to author pages. The URLs of author feeds are also changed.
Visit the <a href="http://www.microkid.net/wordpress/author-slug/" title="Wordpress Plugin: Author Slug" rel="nofollow ugc">plugin’s homepage</a> if you have any comments questions.

Custom Author URL

Customize the author slug in the permalink for author pages.

SEO Slugs 4 bbPress vs Custom Author URL