Though it’s been a gradual process I have completely switched from using Outlook to using Google Apps for calendaring, contacts and email.  When I started using a Blackberry about two years ago I was using blackberry’s desktop application but infrequently.  I needed a way to keep everything up to date and found Google’s Mobile Sync App.  I prefer it because it:

• Synchronizes wirelessly.
• Works with contacts and calendars ( I have multiple Google Calendars)
• Runs in the background and doesn’t “take over” during a sync process.

The only reason I ever connect using the Blackberry desktop app is to backup and sync media files.