Delicious

In my opinion, this is a very good way for a student to research something. By simply entering a search term, they can find the sites which people consider to be the most useful on the topic. At the same time it is still the internet, and the information may still be slightly questionable.

Inspiration

It seems like this would be a very good program to help students brainstorm for their assignments. While this is the case, for the most part it would not be the most useful of software for my future classrooms (choral music.) At the same time, it could be used to have the choral officers help me to brainstorm for ways to raise funds for the program or to help them write papers of their own over musical topics.

Once again, not much writing will come up during Choral rehearsals, but in the situation where the students need to collaborate to produce some ideas, simply using a mutual forum would work well to help them relate their opinions to each other with relative neutrality.
If only plagiarism were not a problem students could also post their written assignments to their blogs for their peers to give feedback as comments. Simply emailing their papers to each other could also prove problematic. Simply put, this won't come up for me in the future unless I am teaching at a school which offers some form of a music history course.

Blogging

In my opinion, blogging can be useful in many ways. At the same time its not exactly likely that every single kid in a class will have both the internet and a computer available to them at home. While this is becoming more and more uncommon, it is still a possibility which cannot really be ignored. As far as communication goes, I feel there is more appropriate avenues for students, professors, and even friends to relate their feelings to each other than an entirely public diary. Some students might have a tendency to say too much online.