By Second p0st.
“Structured blogging” is what people are calling the ongoing effort to make weblog content along specific lines machine readable and aggregable.
“Aggregation” in its current form means bringing a bunch of posts together from different places and showing them in a convenient way – usually either on one page (“Dave Winer” style), with three panes (like an e-mail client – many desktop aggregators do this) or two panes (“Bloglines” style).
Structured blogging is about letting the aggregator understand what you are talking about, and present things more intelligently. For example if you blog an event notification – maybe you’re talking about a concert next week – it might be shown on a calendar along with everyone else’s events. Or if you review something, it can be shown in context. I run a coffee review site, and you might be able to aggregate my reviews with some other local ones. Or perhaps my site could aggregate your reviews, from your blog, and you could see everyone’s coffee reviews in one place.