iPhone and Entourage

I'm pretty sure it's supposed to just work. Apple lists it as a feature/supported app (somewhere, or did). You have to turn syncing on in Entourage preferences, and then contacts should show up in Address Book and also get synced to the iPhone.

I haven't dared to sync contacts because I want to do some manual resolving first (and there are numbers in the phone I don't need/want in my Entourage book), but my calendar syncing from Entourage to iCal to iPhone is working pretty okay.

But you might search on the Entourage forum for pitfalls, best practices--and that's a better place for Entourage/iPhone questions anyhow, as there are MANY more iPhone users there than there are Entourage users here.
http://www.officeformac.com/ProductForums/Entourage/

I'd backup first, in case it goes wonky.

Entourage doesn't sync directly with iTUnes to your iPhone. Entourage syncs indirectly though your iCal and your Address Book programs via iSync.

First, make sure you have reset all sync settings. Go into iSync (in your applications folder); in the menu bar select iSync>preferences> reset sync history

Then make sure your sync is enable in Entourage -- it's under preferences for syncing. Sync with iCal, sync with Address Book

Before you sync your iPhone, make sure you open your iCal and your Address Book and assure that your Entourage and your iCal calendars and the address book contacts are now identical. iCal should create a new calendar called Entourage and all those items should now be in your iCal. If they are not, then something is wrong and go back and try to resync them.

If your entourage data is not showing up in iCal and Address Book, it isn't going to sync to your iPHone.

One word of warning -- people have reported consistently that using Entourage can cause duplications in your calendars, and at times, changes made in Entourage just disappear from iCal, and when synced, they subsequently erase in Entourage. This has gone on since the first iPhone, and continues to this day with the newest versions of software.

Personally, I got rid of using Entourage and now sync only with iCal and with Address Book on my Mac. It works flawlessly and no headaches. Unless you absolutely have to use your Entourage for work reasons or the like, I would recommend NOT using it if you are going to be syncing to a smartphone. To do this, once you have synced Entourage with the mac programs, go back and deselect the sync options in Entourage preferences.

Good luck -- theoretically it should work just fine. Practically, your not going to be happy syncing to Entourage.

I've been using Entourage and syncing successfully for the last year. Only once or twice have I had any duplication issues.