I've been reading about the Semantic Web for about 3 years now. It makes sense to me that web pages should be readable by software as well as by people. With the right software you can tell from my site where I live, who I know and what sites are about me. Of course, you will only get the information I choose to share. It's disappointing that more people are not making use of these technologies. They allow for so many cool things, like finding out what web sites are based in your area. Ultimately they could make search much more effective, even bearing in mind an old essay by Cory Doctorow.
In the last couple of weeks things have started looking up. Firstly I found Foafing the Music that looks at my FOAF (warning, site not updated in ages) file and tries to work out what music I might like based on what information I have there. Interesting, but just a toy for now.
This week I read about Six Apart adding semantic features like FOAF and XFN. They also use OpenID, echoing my thoughts on open social networks.
A comment elsewhere on that story revealed that photo site Smugmug was also getting on the FOAF/XFN bandwagon.
I've written one small program that collects geographical information from a set of sites to display on a Google map. I'd like to do more in that area.