I was already tagging my posts as I went along, so I don't need to do that. When I set up my LibraryThing account last year, I used tagging to keep my 'piles' of books separate.
I tend to think of tagging as being a tool to make sense out of a whole pile of stuff. I really wish our online OPAC had this capability, but it doesn't. Once I'm done with school, I'm seriously considering loading all our library's books into LibraryThing for our patrons to use. In that case, tagging would be essential. The books would be on the physical shelves in alphabetical/DDC order...but it would allow patrons to locate the materials by how they think of them, not how we think of them, especially in the non-fiction area. That's what I love about tagging-just because I think of an item in a specific way doesn't mean anyone else does. Besides, half the fun of looking at tag clouds is to see what others call the item being tagged!
I have used del.icio.us in the past, and I love the concept...but maybe not that particular site so much. On our main terminal at work, under the staff ID, I have bookmarks that are useful. Inevitably, though, the one I need is on my home system! Loading them all into an online bookmarking site is a better idea, and then we can all tag the sites how we remember them for ease of use.
When I set up the Delicious account, all of my bookmarks from my home computer got ported over...yikes! I didn't know I had over 900...but I do now (no wonder I can't seem to find things). I ended up just deleting the new account (and all the bookmarks) and starting over rather than deleting everything one-by-one.
Can you see the potential of this tool for research assistance? Or just as an easy way to create bookmarks that can be accessed from anywhere? You know, I can definitely see the value of this tool, especially in a library setting. In the fall, area students have to do a leaf identification project, and many come to the library for books. It would be nice to have other resources to point them towards, and this might do the trick. It's also a great thing to be able to access my bookmarks from anywhere (the library or school) instead of just at home.