I have the same problem, and I think the best solution would be to index my web browser search history and be able to search through that index. However that would probably generate a lot of junk. My current solution is to bookmark anything that's vaguely interesting. And when I remember something, I search through the bookmarks. I never look at them, they're just for keeping the stack of stuff to search through.
I am using the same approach too. However, most of the old stories I had liked at HN were not bookmarked, so I had to struggle writing a scaper for them.
It would be very cool to be able to authenticate and grab all my saved stories and the comments for archiving and fun!
