Social bookmarking can be an essential tool in areas like research or tracking online resources not only for students but in all areas of academia. CiteULike seems a great resource. A quick search on my senior thesis topic brought up a ton of great and interesting stuff.
However, I have to admit I'm not completely sold on social bookmarking. The idea is great, being free from your desktop browsers so you can have access to your bookmarks wherever you are. But, for me, it doesn't seem to seemlessly integrate with other web 2.0 applications the way you can say post to your blog from google documents or even your mobile phone. Just another list of something you have to keep up. Taging and bundling seem to be the best feature of Del.icio.us. I have used tags very sucessfully in gmail for keeping track of personal and consulting projects. It's like folders only better because one item can have multiple tags for cross referencing instead of having several copies runing around in different folders.Have signed up for a Del.icio.us accounts so we'll see how it goes. In time I could be taking it all back.