Labels and Duplicate Content

I recently switched over to Blogger's new beta version. One of the new options is to create "labels" for posts, which categorize posts for later searching. You may have seen this sort of thing on many Wordpress based blogs. But as I thought about the option, I began to think about the effects it would have on duplicate content...

If you archive your posts like I do, a unique URL is created for each post. Because of this, duplicate content is generated as long as the same post resides on your blog's index page. This isn't really that big of a deal though, as your index page will most likely be filled with other posts, watering down the exact percentage of duplicate content between the two URL's. But Labels are a little tricky, at least in the beginning.

Since I've used Labels, I've created two posts, both under different and new "labels." When published, not only do I create a unique URL for the new post through the archive process, but the same content is re-published under it's new label. At the moment, I only have two labels with one post assigned to each of them. This, combined with the unique URL that is assigned for the post's archive, creates identical content. I guess I could fix the problem by going through every single post I've ever made and assigning it a label, but it sort of seems like too much of a hassle. Until then, I plan to just ROBOT.txt my labels folder, to protect the site frrom any duplicate content penalties, and maybe when I have enough posts in each label, the dup. % will be low enough to un-ROBOT.txt the folder.