Rendered Url in browser & Digg Script & meta tags

Question 1)
How can i get my dynamically rendered page URL where it says digg_url??

<script type="text/javascript">
digg_url = 'www.slangasaur.us';
</script>
<script src="http://digg.com/tools/diggthis.js"
type="text/javascript"></script>

so i can have digg voters, vote for that specific page, not just one
static page i type in.

Question 2)
how can i dynamically add keywords to a page, such that on

http://…/urban/english/some_phrase

my meta tag inside of my layout renders this pseudo code correctly

<% if some_phrase !== nil %>
   <% @keyword = some_phrase %>
<% else %>
   <% @keyword = "" %>
<% end %>
  <meta name="keywords" content= <%=
@keyword+"these,are,other,keywords,i,need" %> />

(BTW the above doesn't work, or i wouldn't be asking)

Question 3)
how did you get so awesome at rails??