Reddit greasemonkey script: see a headline ONCE

For reddit freeloaders like me (i.e., readers who rarely care to vote), one slightly annoying thing about reddit's presentation is re-reading the headlines I've already seen. So I wrote a start towards a greasemonkey script to make it easier to ignore stuff. Usage: when I look at a reddit page, I scan all of the headlines, and hit my scroll-wheel-button ("Open in new Tab (in background)") on any that I care to look into. With this script, I never have to do anything else in order to avoid ever seeing any of the other ones again. The script is here. Bugs: It inappropriately eats the comment-submit box/button; I should disable it on comments pages. Next to do: It needs a toggle on-off key, and it might be nice to shrink and pale-ify the already-seen headlines, instead of removing them altogether. For reddit to do: when I open a raft of tabs from a reddit page, I sometimes forget what reddit submitter-supplied headline made me choose to read this page. It would be nice if reddit could arrange to have the "referrer" be the comments page for this entry, instead of http://reddit.com/?offset=25 . Nicer would be to set it up so that "Back" would work even when I did the open-in-new-tab trick. Bonus: The script works on ycombihacker news, too.