Maybe I finally have all my sync issues worked out
The first problem was getting my Exchange calendar into iCal in my work account on my Mac. The more recent patch release of Entourage have support for Apple's Sync Services. Theoretically this means that Entourage will sync my calendar (and contacts if I want) between both our Exchange server and iCal on my work account. Then iTunes will sync my calendar from iCal on the work account to my iPhone. Then I have my work stuff.
I had enough trouble getting Entourage to sync with iCal that I actually paid $245 to open a support incident with Microsoft. The two free warranty incidents I have from buying office couldn't be used, because Microsoft Exchange was involved. After spending several hours with Microsoft support, including a few where they were remote controlling my Mac, with no success, I decided to get extreme. I found this hint, which was extremely helpful. The Syncrospector tool I got allowed me to completely empty the synchronization history. I then used the Microsoft Office database tool to rebuild my Office/Entourage database, and after that the sync worked just fine. Since I figured this out myself, Microsoft refunded me the $245.
For m personal calendar and contacts, I want to maintain that in my personal account on my mac. Then when I sync my iPhone with my personal account, the iPhone will end up with both work and personal calendar items, and work and personal contact information.
Since I used to use iSync to sync both work and personal contacts to my Motorola E815 (via bluetooth, which the iPhone hopefully will do eventually), both accounts had a blend of information, much of which was incomplete. Unfortunately I fixed it over a couple of days in three different locations (some on the iPhone, some in my personal account, and some in my work account). This created a mess where every time I synced I got lots of conflict popups. So I went through and deleted all of my work contacts in the personal address book, all of the personal contacts in my work address book, and used Syncrospector to clean the syncronization history of both my personal and work accounts.
If I can go a week or two now without a sync conflict, I'll begin to believe that I'm through the worst of this.