is it possible to normalize a rss feed to remove duplicate links?

I don't know perl but I think I would do this client side anyway.  Create an array of links.  For each post, first find the links and see if they are in the current array.   If not, add the link to the array.  If the link is in the array, then don't use it.  If there are not that many tweets you are checking, there may be no difference client/serverside.

does not have to be perl, i didnt know where to post this

What language do you work in?  I'm sure there will be multiple ways to do this in any language.  

You would want to look at a post, then find each string starting, "<a " and ending in "</a>".  Then from the complete string <a href="http://mypage.com/link">Link</a> take just the mypage.com/link and add that to your array.

Then for each post look for a link, if the, "mypage.com/link" matches what is in the array, then do not use the link or post.  

I think you will find this harder though because the same link may be shortened with different url shorteners. If that is not a problem, this should work.

I do not. I am  going to hire someone and am budget insensitive.

Yes, but I think there is a system that could return true URL