For those of you who run their own Exchange environment, RIM is now offering a free version of their Enterprise software. This will allow you to sync Contacts, Calendar and E-mail over the air.
This is a great move for RIM who had always been known for only being a good option for large enterprises due to the high price tag of their Enterprise software. I have the professional version running at a few customer sites and it does a great job. The express looks pretty similar to the professional version sans the price tag.
Download directly from RIM... http://na.blackberry.com/eng/services/business/server/express/