Permalink
This plugin helps you use a consistent permanent link format by generating permanent links for you. It does this by exporting two variables, $permalink::story and $permalink::category, which contain the permanent link for the current story and category, respectively. It also provides a function permalink::get_link() which can be used by other plugins when they wish to get a permanent link for a file.
I also have some patches for blosxom.cgi and some other plugins that make them use permalink:
Documentation is available here.