Is it possible to keep Contact List and Address Book seperate on iPhone?

Question

I just made the switch today- big time – from Motorola to iPhone, and from PC to iMac, plus a Macbook Air as well for travel. Thanks to iphone and Mac forums I have been able to resolve most newbie issues and have exported my data, files and contacts without problem.
However there is one issue I have not been able to resolve or clarify:
- My old phone contact list has now been transferred my new iPhone, consisting of about 100 phone numbers which I use regularly.
- Address Book in my new iMac contains about 800 contacts including phone numbers, clients, etc, as well as personal bank account numbers, and other confidential data in the “Notes” field, which I need to refer to only occasionally.
But I understand that if I sync my iPhone with my Mac, it will merge my Address Book contacts on Mac, with the phone contacts on my iPhone Contact list, into one list. Is this true? Is it not possible to maintain 2 separate Apps on my iPhone, i.e
1. The iPhone Contact list for frequently used telephone contacts, and
2. The Mac Address Book with more detailed notes and account numbers, which I only need to refer to occasionally?
3. If this is possible, can I configure it so that a password is required each time the Address Book on iPhone is accessed? (I realise I can configure the iphone to require a pin when turned on), but I would like a password to access the Address App because of the confidential data. Previously I had all this data contained on a Palm Zire 72 handheld and its PC Desktop counterpart, where a password was required to access.
From what I’ve read on the forums, it will be very cumbersome to have a phone contact list with 1000 names on it, so I want to keep phone contacts simple with phone numbers only. (I realise I can set up Group folders in Address Book, but this is not what I need). I'm also concerned about having confidential information on my iPhone which can be accessed without a password for that particular application. I intend to get MobileMe but that also does not address the issue of keeping Telephone Contacts seperate from Address Book on iPhone.
Any help would be much appreciated!

Answer 1

Speculating:
if, as already suggested, you use the Groups function to sync only the 100 contact list numbers, then how to get the expanded Address Book?
I've not used it myself, but Bento might be worth looking into--Bento on the Mac pulls your Address Book data (I'm pretty sure) and syncs to Bento iPhone.
I don't recall hearing about any alternate phone books, but since pretty much any program on the Mac can hook into the Address Book, you might look at the more powerful note organizers to see if any of them pull that data?
You might have a problem getting notes added on the phone back into Address Book on the Mac, though.
I actually right now keep my main address book in MS Entourage (similar to Outlook), and only use the Mac Address Book to sync to the iPhone. I could sync Entourage to Address Book, but I don't--haven't sorted out the data yet, and I don't really need all the same numbers in both places.
If that sounds possible, you might look at Mark/Space and Missing Sync for iPhone---something like keeping all 800 contacts in Entourage, and syncing them all, but moving the confidential portion of each contact into Entourage Notes and syncing those via Missing Sync, perhaps might work. (I think you can link a contact to a note in Entourage)
An interesting problem. You might also send feedback to Apple:
http://apple.com/feedback/iphone.html
as this is really not a usage scenario they've planned for. They probably don't care, though--doesn't seem all that common.