I did not find Delicious and Technorati to be as user friendly as Rollyo. I understand that it is convenient to be able to access one's Favorites from any computer, but I had trouble navigating around these sites.
I enjoyed reading the Library 2.0 articles more than I did browsing through Delicious and Technorati. I agree with many of Rick Anderson about the need to avoid those icebergs. I know many librarians who feel the need to keep things "just in case." It's time to let go of that notion and stop hoarding things in case that elusive "someone" may need it.
I think that most of us in the profession understand that libraries no longer have a monopoly and must rethink the idea of service. Our profession has risen to this challenge and has done its best to remain vital. It is though a never ending task to continue to stay that way.