Radio Free Blogistan there's an entry about archive navigation:
One Movable Type feature I really like is the back and forward links built into the standard template. Since I generally have many posts per day, I'm only showing three days right now on my home page. I'd like it if at the bottom of the page there were always a link to the previous day/post. That shouldn't be so hard to do, right? [Radio Free Blogistan]
This is something I'd love to see, as well as a better handling of going back to a specific month. I'd love to see an index.html at each level of the archives. One for the year would list all the months that have posts (or maybe just redirect you to the first post of the year). And one for each month that would redirect you to the first post for that month. It would make things so much friendlier I think.