Blogger has published an article on how to hack the service to add greater customization by tweaking its template vocabulary:
For instance, most of our default templates display archive links in a list. But really, the archive tags simply provide the names and URLs of all the archive files, and we can do whatever we want with them. Do you know how to make a pull-down menu in HTML? Think that might be a more efficient format for your three years of daily archives? Great! Move the archive tags out of the list and into a menu.
(via EvHead)