I’ve added a new feature to the display of archived posts here, requested by my friend Oliver back in August:

What do you think of putting “next” and “back” buttons on the pages of your archived permalinks? The current set up makes it un-straightforward to read through a sequence of old entries, which I suspect must be a common desire (say, if one of your readers was away for a week and decides a month later to go back to read what she missed, or if a new comment on an archived blog peaks a reader’s interest in thoughts on that topic that you might have blogged in the hours or days immediately following).

Done. Good idea.