Source URL mod

I often post stories taken from websites, so I thought up a blog type mod that could add a text box for posting the URL to the source and proceed to post it automatically at the end of the post. Like say a grab a story from CNN I could post it, paste the URL and it would automatically change the link to the text source placed neatly at the bottom of the page, but customizable so you could post it at the beginning, end, right, left, or center. I thought this would be a simple mod someone out there could create, I can't be the only one.

TIA