Things that would be nice to fix with URLs.

  1. Drop the //, http:google.com is shorter and easier to read. Tim Berners-Lee regretted putting those 2 extra characters when he started the web.

  2. Inverse domain names. Example: sub.domain.com, com is the top level, and sub is the bottom level: domain names put the top level last. Path in URLs do the opposite, the top level is first:

    http://sub.domain.com/blog/2012/04/18/
           <--<------<---+---->---->-->-->
    

With those principles in mind, new URLs would look like that:

http:com.domain.sub/blog/2012/04/18/