Override default url for author pages?

So the default url to display a list of posts by a particular author looks like this:

http://domain.com/author/{username}

I am wondering how to change the ‘author’ in that url to something else?

I am working on a website for a charter school and they would like to allow each teacher to have a list of posts by “classroom”. So the desired url would be

http://domain.com/classroom/{username}

You might wish to try..
http://wordpress.org/extend/plugins/custom-author-base/

Hope that helps.. 😉