how twitter changed the get question mark on the url <p>i wonder how twitter did their URL like this</p> <blockquote> <p><a href="https://twitter.com/#!/twitter" rel="nofollow">https://twitter.com/#!/twitter</a></p> </blockquote> <p>is it a unique method via ruby or it's something i can do with .htaccess and php because as far as i know this # sign is used to send user to a certain block on the page</p> <p>also is it possible to use other tags for example &amp; or % or $ etc.</p> <p>thanks in advance </p>