Same address book for multiple users??

There really isn't any simple way to accomplish what you want. MobileMe's sync facility would be the easiest thing to use. It's configured easily:

Open MobileMe preferences (sign in if you need to) and click on the Sync tab. There's a list of items you can sync of which Address Book is one. Turn syncing on by checking the Synchronize with MobileMe box. You can then set the frequency from the drop down menu or set Automatically. Then check the box to the left of the items you want synced to your MobileMe account. Check the box to put the status icon in the menubar. Click the Sync Now button. The Address Book is listed as Contacts, btw. The initial sync will request the direction which initially should be to transfer FROM your computer TO the MobileMe account. Thereafter the syncs use automatic Merge. Now, your husband must configure his computer's MobileMe preferences the same as yours. Only he should select the option to Merge with the existing data on MobileMe. Now any changes either of you makes to the Address Book will automatically get incorporated into the data store on your MobileMe account. If you set the sync to Automatically then you don't need to do anything more.

Now, be aware that you cannot maintain two separate accounts and use one MobileMe account to sync them. Whatever data is uploaded from one of you will replace the data on the other's computer. So you should only choose to sync the data you want to keep in common such as your Address Book entries. if you wish to use MobileMe to sync your other, private, data then you need two MobileMe accounts - one for you and one for your husband. You can still use one of them for the common Address Book, but the rest of your data would be kept on your separate MobileMe account.

I suppose although it would mean you have to purchase a family license for the multiple accounts. You can't have an extra MobileMe account for free. The family license is good for five different accounts, I believe, and is an extra $59 per year.

And, yes, to sync to your personal account would require logging into that account. It wouldn't be automatic as far as I am aware.

I am replying to this thread because I have about the same situation as mome. My wife and I each have a user account on our old G4 mac book and on a brand new imac. I am most interested in either of us be able to get our mail on either machine without having mail showing up in the others mailboxes which happened when I tried to accomplish the goal. I have a mobile me family pack with my wife as the sub account. Can you help me get the mail accounts set up to let us use both computers? I would additionally like to have our calendars and contacts synced but this is not really critical to us. Thanks in advance for any help you can provide. I tried to use Apple's chat with an expert twice but never got the to understand what I was trying to do.

I have the opposite issue. I set up my wife as a sub account on our family account, but just want her email to sync online and with her accounts on other computers. However, I turned sync on, and its pulling my contact info and mail over.... How do I get her sub account to act as it's own distinct account for syncing and not merge our info?

Are you both using the same computer? You will need to set up a separate user account for her. Any one user account can only work with one MobileMe account: when you enter the username and password in System Prefs the information is used by Mail and iWeb and in syncing. While you can access another MM account's iDisk easily enough, for the other facilities you have to have a separate user account where you can enter the username and password for the second MM account.

I have the same need as well. We are repacing our Dell with an iMac for Christmas. Presently my wife uses outlook on the Dell and I use mail on my macbook. We synchronize address books using mobile me but there must be a more elegant solution.

Can we run addressbook server on our iMac using an administrator account?
Alternately, since I have a home network, can I run some CardDAV server on a linux box? I was going to set one up to run subversion anyway.

All attempts I have made to share Address Book data between two user accounts on the same Mac have failed. The usual tricks that work for sharing other stuff like iPhoto, iTunes, iMovie projects (moving the data to a shared space, changing permissions, adding ACLs and symlinks) have failed for Address Book; it all results in the Address Book data being locked for everybody but one user.

Syncing through MobileMe seems to be the only way to get it to work.

Or do it manually. Export all your contacts to vCards, move them to ~/Public, log in to the other account(s), copy and import them.

PS to the other posters: Please don't append "I have a similar/opposite issue to the OP". It makes the thread confusing and takes attention away from the OP's issue. It's better to start your own thread.