Better duplicate identification
joshfinnie: I think if you make it an initiative for the submitters to submit the lowest common demoninator, we would rid ourselves of the duplications.  I have to believe everyone on Hacker News knows how URLs work and can see that something like this:    ?utm_source=feedburner&utm_medium=twitter&utm_campaign=Feed%3A+startup%2Flessons%2Flearned+%28Lessons+Learned%29

is not needed as part of the submission URL.And to cover all basis, if you don't know if it is needed try it before you submit it to HN. Delete the above portion of the URL, hit enter and if you still get the same webpage you have done your due diligence.  Finding a correct algorithim for this might be tough, but if we put the pressure on the submitters themselves we might get something done.