For years, my employer has been almost anti-Microsoft. Yes, we always had Windows laptops with Office on them, but the entire network backend was Sun. My mailbox is on a Sun Java System Communication server, which I access via LDAP. We also have a Sun online calendar server, but I've never used it. I've actually always just had Outlook on my work machine also access my personal Exchange account. Tasks, Calendar entries, and Contacts lived in my personal account, and was easily synchronized to my phone.
Now my employer is testing Microsoft Exchange as a mail and calendar environment. I'm not on that pilot, but I do have a new laptop with our newly released Vista image, which appears to assume I'm on that pilot. I attempted to add my personal Exchange account to Outlook, which ended up in a vicious cycle of authentication pop-ups for the Global Catalog on my personal network and the work network. This has caused it to have a ton of trouble actually receiving any mail. I usually take my Mac to the office, and Outlook Web Access works quite well, so I don't have an issue reading my personal mail, but I do only want to have a single calendar, which is available to my on my personal machines, on my phone, and on my work machine.
After a bit of Googling, I decided Google was the answer. Google calendar and the Google Calendar Sync plugin for Outlook. Basically what this does is on a scheduled basis, it synchronizes your Outlook calendar (in my case a local PST based one on my work machine, and an Exchange based one on a machine on my home network) with your Google Calendar. It can either be two way or one way (you specify which one way.) I'm using two-way on both machine. So far I haven't had any sync issues.
My only complaint so far is that Google's calendar doesn't have any tagging, labeling, categorizing support. Using the web interface only, you can create separate calendars, and they are color coded. I suspect that this is how they intend people to segregate their different appointment types. Unfortunately, the Outlook sync app can only sync one Outlook calendar with your main Google calendar. I generally categorize (which color codes) all my Outlook calendar items. Personal, work, Scouts, etc. Unfortunately for now, all that data doesn't make it into Google's world, so also doesn't make it back and forth between the two copies of Outlook.
I was hoping that Windows Live Calendar would be a solution, but it doesn't seem to sync, that plugin seems to add Live as a new data store in Outlook. Thread here.