I wanted to announce a new plugin, WP-Smartdate. Quite simply, Smartdate looks for relative date expressions in your blog posts, such as "tomorrow," "this coming Monday," "last Friday," looks at the current date, and computes what day you were referencing in plain old English. WP-Smartdate then puts a machine readable reference (like "2007-11-26") in an abbr tag microformat. I hope others will find it useful.
The complete announcement (with some extra details) is on my blog at Introducing Smartdate. The plugin is still in its immature youth, but I would love to hear your comments!