My company uses Novell GroupWise for email and scheduling, while I use Outlook for my personal calendar and this presents some challenges when trying to keep one calendar in sync to show both business and personal events and then trying to sync to mobile devices. I have tried a few 3rd party GroupWise syncing solutions (my favorite is PortaMail/SmartSYNC) and they work fairly well if you stick with a single mobile device operating system. As a mobile enthusiast I change devices frequently and want flexibility in my syncing solution. You can also use your GroupWise calendar via a web interface using their web access module, but this requires a wireless data connection and has a poor user interface that runs with Java and limits functionality on mobile devices. I currently have separate work and personal calendars where my work calendar remains on my desktop and my personal calendar is managed with my mobile devices, MacBook, and other PCs using a hosted Exchange service. I love the way the Exchange server solution allows me to keep a single calendar in sync and wish I could do the same with GroupWise.
Lately, I have been using Google Calendar since I enjoy using the Ajax interface and can easily view and share calendars with family and friends. I am also a Gmail fan and user so the integration with Calendar is another bonus. Google made their APIs available and it looks like CompanionLink Software is the first to come out with a way to sync Google Calendars with Windows Mobile, Palm, and BlackBerry devices as well as Outlook, GroupWise, Lotus Notes, and Palm Desktop with their CompanionLink for Google Calendar product. If the software works as advertised then I won't hesitate to pay the US$29.95 for a solution that brings Google Calendar syncing to all my devices and PCs.
I just downloaded the 14 day free trial and will load it up and attempt to sync my work GroupWise and personal hosted Exchange calendars to Google Calendar as well as to my mobile devices and am quite excited about the prospects of this application. Since the Google APIs are still being modified there are a couple of known issues, such as no support for recurring events.