The understanding of the usefulness of authority control has certainly been emphasized throughout this lesson. Having subject headings allows searchers to share the same language and as such should enhance access.
Being introduced to social bookmarking was very interesting and something that I can see great potential for in sharing resources with teachers and curriculum topics with students. Being able to share your findings with others so that they and you have access from either the school or home computer is great. It is also nice to be able to create your own tags and add brief description to serve as a reminder/introduction about the content of each of the sites.
I played around with delicious.com and registered. I found it a little frustrating to add links it didn't always work - so I guess I need to use the site a bit more to get the hang of it. My site containing my stack about resources on social entrepreneurship was www.delicious.com/stacks/view/GsnHF7 - hope you can view it. 
Social bookmarking is definitely something I would like to explore more of both professionally and personally. I see great potential for sharing among a staff wide account for resources members of our staff have found that would be relevant professional development material.