How to share entire address book? Only after setting up my girlfriend's and my own Lion user account to sync with iCloud did I discover that the address book still doesn't lend itself to sharing in the way that calendar does :-(

We currently use a single iTunes library on my user account for syncing both of our iPhones to a single address book, where all her contacts are in a folder called "girlfriend's contacts". This allows us to share our contacts but still (in a way) keep them separate.

What I'd like is for her to keep all of her contacts in her own, separate address book in her existing user account on my computer. We would then share our address books with one another (read-only or not).

Is there a work-around using iCloud or any other service? I guess we could continue syncing our contacts in the old way via my iTunes library (effectively mirroring our combined contacts in two separate iCloud accounts), but that's not very elegant...
You can set up multiple different iCloud accounts in the "Mail, Contacts, and Calendars" preference panel, and also on your iPhone and iPads.

I have accomplished a shared address book with my partner by each of us having a primary iCloud account (me@us.com, her@us.com) - and then a shared iCould account us@us.com.

One annoying downside is that the Lion Address Book app labels both address books as "iCloud" making it a bit hard to distinguish what contacts are where.  We solve this by having different contact lists in each address book, so they are distinct.

It seems with just a little bit of work Apple could make this MUCH better, but this is the best solution I have seen so far.