getting to classroom tools

To work off of my last post I have a very simple question. Should a school provide email addresses for their students? A simple question perhaps, but not so simple of an answer.
As a said in my last post, there are so many free Web 2.0 tools out there which can be used by students (and teachers alike) to make the classroom a more exciting and interesting place. The downside? Most of those tools involve having an email address to register. Want to use Google's Doc and Spreadsheet - need to have an email address. Want to sign up for a blog or a wiki - need to have an email address. Want to download podcasts - need to have an email address. How about twitter, skype, youtube, etc? All need an email address. There are so many of these tools that someone has created a site where you can get an email address which lasts for 10 minutes (the site is called 10 minute mail).
So what is a school to do? You can't just give all the students email addresses and say good luck. Too many bad things can happen. Do you have all the messages go through the teacher to monitor them? You have now given your teachers a whole lot more mail and taken up a whole lot more of their time. What about if a student does something inappropriate (bullying, threatening, etc) while on your email accounts? How is the school held accountable and how do they hold the students accountable? All tough questions.