The HTML for your microblog posts can be styled with CSS. The CSS class names include:
microblog_timeline (for wrapping all the posts),
microblog_post (around a single post),
microblog_text (for the post HTML), and
microblog_time (for when the post was created).
Sidebar.js defaults to including the most recent 10 posts. To show more, you can add
&count=25 at the end of the URL.