Believe it or not - I think the one feature of ColdFusion 8 I haven't tested at all is the Microsoft Exchange functionality. It looked cool and all (check out Scott's nice article on the feature) but I had no way of testing it. Today I ran across this article:
Keep in Sync With a Free Exchange Server
This describes a free Exchange service at Mail2Web. I signed up and then pointed my ColdFusion code at the account and it worked like a charm. I just tested mail and contacts, but it looks like it supports everything ColdFusion's Exchange API does.