As reported here, here, here, here, and here, the giant open research archive arxiv.org for physics, math, and computer science now supports not just RSS feeds for newly added papers but also trackbacks, which means that if someone posts comments on an archived paper at their website or on their weblog, a link to their page can auto-magically appear on the abstract page at arxiv.org. This is very cool.

I wish that the semanticsarchive had an RSS feed for newly added papers. Trackback would just be icing on the cake.