I've seen services that will shorten your URL when you post them on other sites. So instead of putting your link as "website | directory | subdirectory | html" it would be simply "service | d23ty" I know this is useful for sites like twitter (which uses nofollow anyway), where you have limited space, but does anyone know if it slows your SEO efforts by using that where you're forced to? I've tried searching the forums but couldn't find anything addressing this - if I've missed the post, I apologize and would love to be politely directed to it.
I am sure SEs are discount redirects from popular URL shortening services, I only use them when there is a lack of space (forum SIGs), otherwise a keyword rich URL is always better.