I know it is a funny question but it is still considerable. Recently Matt Cutts warned the search engine optimization community for creating links via guest blog posting with the intention of increasing search engine ranking.
If you will look at the url of this post it is
If we use the default url by wordpress it should be
Matt Cutts used the custom URL and use the only keyword “guest blogging”
It can be concluded that Matt Cutts want this post to rank for guest blogging ”guest blogging” , “guest posting,” “guest blog post”. There is nothing bad in this rather if this post rank the all blog owners, bloggers and blogging company can know better about guest blogging for SEO or otherwise.
One conclusion which I drawn from this that keywords in URL play the role in SEO, This is the reason you find guest posting keywords in above Matt Cutts post title
If you will see the post is ranking for keywords ”guest blogging” , “guest posting,” “guest blog post”