Here’s an interesting blog about Microformats. That’s a new term for some of the old stuff on the net. RSS for example is a microformat. The Microformat site (www.microformats.org) defines Microformats as:
Designed for humans first and machines second, microformats are a set of simple, open data formats built upon existing and widely adopted standards.

Here’s an excerpt from the blog:
Microformats are XML schemas for small things like address cards, calendar entries and even wiki or blog entries. If everyone uses the same format, integrating information across multiple systems becomes very easy.

Link : Innovation Creators: Microformats are the Nano Technology of Web 2.0