Before getting to this 'Thing', I had come across Delicious, but never actually played with it. Looking around the various examples, I was quite impressed with it. As a personal tool, I can see the advantages of it, as one who has access to a number of different computers at home and at work. Equally I can see that if one has a job where one moves around - for example demonstrating information skills to groups of students - having your links at your fingertips could be very useful. In a static library setting I am less sure - the ability to be able to tag webpages with one's own tags is good, but unless your users can also tag them, I am not sure that they would necessarily find them any quicker using Delicious as opposed to a 'static' website.
Next step was to try and set up a Delicious account. This entailed setting up a Yahoo account (I am sure I had one years ago, but the details escaped me)...I am afraid that as they virtually wanted one's life history, I felt uncomfortable going any further. Here I had a bit of luck - my husband has a Yahoo account, so we set up a Delicious account on that. My view was that Delicious was very easy to use - once we spotted that tags were just separated by spaces not commas. Setting up Tag bundles enables one to sort into 'folders', which looks useful.
All in all - a useful tool, but not one to rave about.