This really deserves a fuller posting than this, but the gist of it: Microformats are a way to make your data more machine-friendly, related to (but separate from) the Semantic Web movement. There are several microformats out and seeing use, including hCard and hCalendar. Several more microformats are currently in draft form, such as hReview, and hResume. What’s really nice about this is that it makes your content readable for both humans and machines, and their extensive use of classes allows a built-in versatility in layout via CSS.
Of course, the drawback is that it’s more cruft to try and remember to implement. The folks spearheading the movement seem to understand this, though, and most of the drafts and specifications have online creators that you can use, and several plugins for popular blogging applications (like WordPress) are in development. I just used the hResume Creator to create a basic resume which I’ve posted here.