One of the things I have been working on for the last year has been Google Apps education edition. This is the student mail solution that we are using at school. In the last couple of weeks I have been using the Google Apps desktop features to carry on doing work and communicating with my year 13 programming class.
Google Apps desktop features
Allow users to install Microsoft Windows desktop access points to Google Docs, Calendar and Gmail that are pre-configured to work with accounts on your domain. These apps launch in a streamlined Google Chrome browser window.
This update also allows users to set Gmail as their default email program.
Each domain has a unique download URL to enable the pre-configured settings for your domain.
To get started with desktop features, visit the control panel Advanced settings page.
from google website - updated 5/22/2009
Next step will be looking at Active Directory /LDAP support, though this will require a huge amount of work tidying up user accounts within out Active Directory. In some cases this will also require the Student Management System to integrate into Active Directory as well so it is all managed from one spot.