During my thesis research (2005) I did some experiments with autogenerated tags and extracting tags from userinput. I think this will work just as well – or even better – than giving tags for each posting you do.
wilbertbaan.nl now has a tagcloud autogenarated from the contents of the blog. A script reads the text and filters certain words.
The only thing missing is a library for conversion from hyponyms to hypernyms to narrow the set of tags (for example turn the tag red into the tag color). A system like this is used in Medialandschap to generalize the set of data.
So, this is what this blog is all about… a lot of Video, Google, websites and Flash ;)