I'm new to social bookmarking. I like the idea of being able to organize bookmarks on one website instead of on one computer. I can see how using delicious can become addicting. I'm already linking several sites to it. With Firefox, I installed an add-on so that I can see all of my tags and bookmarks at once. (I wasn't sure if I should have done that or not). I'm thinking of adding the sign-in pages to my email so that when I'm on my computer, I'll automatically go to delicious first and then anywhere else I need to go.
Social bookmarking is something I would like to start using right away in the classroom. I give students a handout with links to Spanish websites or English writing sites, but now I can send them here and tell them to follow the Spanish or English tags. They'd have access to several sites without having to type each one in. Many of the novels we read are in online text on the web, and so I could provide links to literature. That way if a student forgets his/her book in his locker, he can still do reading online.
I'm also thinking that students could set up an account and set up tags for other students' blogs, too; an alternative to using blogrolls.
I'd like to hear more ideas about ways other teachers have used social bookmarking.