Not sure if people want or need this, but my work is a Microsoft shop (Microsoft Exchange)....who isn't? Anyway, I didn't want to pay the extra fee for Exchange Server support on my iPhone data plan, I went with the standard $30. So I was successfully able to get my work email working on the iPhone by using IMAP, but one thing I was bummed out about was not getting my Outlook Calendar sync'd to my iPhone. I don't set up iLife (iCal and Mail) to sync up with the Exchange server because I have thousands of emails (due to work requirements) and I don't want all of those downloaded to my Mac HD, which sync'ing will make it do.
So my challenge was how to sync w/ my Calendar in Outlook without sync'ing to the Exchange server.
The answer? I found Google has an Outlook Calendar Sync tool, I downloaded it to my work PC, and it syncs my work calendar to my Google calendar (attached to my Google Mail account), and then I set up iCal to sync w/ my Google calendar. It's a bit of a workaround, but I use both my Mac and my PC everyday so the sync happens pretty regularly, but not instantaneous, and the data isn't pushed to the iPhone, I have to update it via the Mac.