hckr news is pretty cool. I ran across it a few weeks ago, and saw that it embodied very similar goals to what I had in mind. However, since I had already collected snapshots for a long time, I thought, "Might as well give others access to them."
I somehow missed Hacker Slide when I looked through the Hacker News links on Resourcey. Very nifty!
How far back can you go on each site? I see that Hckr News has an endless-scrollbar-like interface, and Hacker Slide seems to cover two weeks. (Those time frames and navigational control might be plenty for most readers, but some of us are a little more obsessive...)