I hope this might help some people. I have an NHSmail account and have just been migrated. I am an Apple user at home, and a Nokia E71 user. This is how I sorted my life out after the migration. It took a long time for me to figure it all out.
Using a full Office for Mac 2008 (not the student teacher edition because this does not support Exchange 2007, but the full one available through the NHS discount) you must update to v 12.1.5.
After you have registered at www.connect.microsoft.com apply for the Entourage Beta here
http://www.microsoft.com/mac/itpros/entourage-ews.mspx It takes around 48 hours for them to approve you. I have the dmg file. I am sure you can find it on the internet.
Make sure you check that you are using Entourage with Exchange server SP1 or later on the application form (which you are with NHSmail), and the full version of Office for Mac. I said 'don't know' the first time and had to reregister with a different address to get approved.
48 hours later you will be okayed for the trial and download the new Entourage. It will autodetect all your NHSmail settings with just your email address and password. Now you have a Mac that runs a full mail programme with your NHSmail. You can add as many IMAP mail accoounts as you like. You DO NOT have to synchronise your address book and calendars. I hear that Mail may support Exchange 2007 in its next incarnation and many of our problems will have improved solutions.
For a Nokia S60 phone e.g. E71, you can use RoadSync (DataViz software, a respectable company) which is an Symbian Exchange client. You DO NOT have to synchronise your calendar, tasks and contacts so you can keep your NHS calendar, tasks and addresses separate and have both private and NHS worlds on the same device.
Of course you can just use Exchange for your calendar, contacts and tasks if you want to. Many people who like Apple Macs will not want to do that! We prefer a world with iCal, Addressbook and Mail