I've added support for categories. Because Blogger does not support categories this requires some hacking. Phydeaux3 has a great tutorial on how to go about adding category support to Blogger using Del.ico.us.
As of now, most blog posts come with a list of the categories they belong to. You can browse through the posts for a category using the pulldown menu under Posts on the sidebar, or by clicking on the category name on the Category Cloud, also on the sidebar.