Planet Larry has kept archives of posts for about five months now, but I just barely added a Google search form to the side nav so you can ... uh, search.
It would be nice to have the archived pages put the dates in the title tag, but looking through the Venus code I couldn't really see a quick way to do that, so meh. I could probably just write a quick sed line to fix it when its archived, I suppose. I'll look at it later. Or let someone else figure it out for me. 
Oh, also, just a reminder, Planet Gentoo stores archives as well, though there's no index page or search index yet. Another item on my long to do list.