I was poking around this morning looking for a way to do a calendar display within MovableType with an offset - allowing users to move forward and backward through months. One of the first results I found on Google was a full-screen calendar output template. It took me about 20 minutes to drop it inside of my own site template, and another half hour to update the style sheets, but it's done. I've still got to work on the main Archives page, but everything is coming together...