Several times in the past week I have clicked on a thread, read the thread for comments, clicked the article link to read, clicked back, and then hit "reply" on a comment. Half way through formulating a comment I think "oh, I wonder if the article touched on $foo" and then have to either unwind the stack or open a new tab to news.yc and retrace my steps. Being able to control-click from the comment page would be ++handy.
Thanks for the site, really enjoy it.