(Thing #13) del.icio.us.and.tas.ty.

At first this looks like yet another link-gathering site, not so different from, say, Google Reader or Digg. Just pick the one you prefer, and stick with one. They're all so general and random, but you can narrow your searches down to anything. But then you realize you tend to be drawn into certain subjects in one, and completely other subjects in another site... you hear your friends talking about Digg, but others only use Del.icio.us and you've got to keep up with all of them. Not because you prefer one over the other, but because you've got different 'conversations' going on in different places. Kind of like having a MySpace and a Facebook profile- you don't necessarily prefer one over the other, you just have different friends, different artists, and different reasons for visiting both of them.

I did a search - Del.icio.us for Librarians and found dozens of good articles and blogs on how libraries, librarians, and library students are using the site. I have a much greater appreciation now! Do your own similar search, as the tags are always being updated and added to.