I am the first to admit there is nothing like trying something out before you buy it and I am glad to say you can now do this for Exchange 2007.
By clicking here you can get an email account for 5 days on a hosted Exchange 2007 server. During this time you can fiddle about with the setting and send/receive email via Outlook, Outlook Web Access and even Outlook Voice Access.
Great if you are looking to play with Exchange Server 2007 before buying and also great as a demo tool
Testing and trying Exchange 2007.