I love tagging in general and think it usually works well enough even without a controlled vocabulary. Folksonomies have disadvantages, of course, especially in their imprecision–users might get both horses and cars under “mustang”–but the advantage in comparison to cataloging with a controlled vocabulary is that people tend to use terms that most other people would find useful too. And of course it’s cheaper to let other people tag things, provided you have someone doing quality control to weed out nonsense and mischief.

Right offhand I can remember using tags (both adding them and following them) on Flickr, Blogger, Wordpress, and Wikipedia.

Still, I didn’t yet have a del.icio.us account, mostly because I visit a handful of sites over and over on just a handful of computers. I set up a delicious account and bookmarked and tagged a handful of sites, then couldn’t include my badge here because Wordpress doesn’t allow Javascript.

Obviously this and other social bookmarking sites could be useful for libraries–we’re all about cataloging and organizing information and making it available to others, so a site like this is a natural fit.

I’m not sure, though, how likely I am to keep going to delicious for personal use–I have a lot of bookmarks at home but don’t use them much. Having them available from anywhere would most likely not change that.