Many teachers would like to use blogs and wikis in their classes. They understand that the more students write, and share what they write with an audience, the better. There are many many ways to do this, lots of free software out there. For the intrepid that just choose one (they all have their advantages and disadvantages) the inevitable bottleneck is the time and complexity of setting up and administering of these accounts.
Setting up individual wiki pages and giving each student access, along with the teacher takes time. If you’re using Google applications you need to gather the google account signons of each student. Most applications require that you enter an email address of some kind to give student’s access. Need I say that this kind of “clerical” work is not what most faculty will take on, even with the carrot of a useful class tool?
What we need is a quick and easy way to gather student emails and have them available for pasting into whatever application we want to use. Solving that issue would hugely increase use of these technologies.