Preserving the correct URLs is a lost cause - tinyurl and services of that ilk make it all but impossible. With regards to content appearing in search engines

Preserving the correct URLs is a lost cause - tinyurl and services of that ilk make it all but impossible. With regards to content appearing in search engines as belonging to both, have you bothered to check or are you making assumptions? Seems to me (from a test on some of the latest Digg stories) that the original author is ranked for his/her post, but Digg is not within the first 5 or so pages. Furthermore, even when appending "digg" to the search term, only the link to the story summary is shown and not the toolbar-clad page.