So I just moved (actually Yusuf moved) my address book to an LDAP server. I thought it would be really cool until I realized that Address Book for the Mac SAYS it does LDAP, and it sort of does, but it doesn't do authentication. Blah. PLEASE PLEASE make address book smarter if you're going to make it the centerpiece of PIM on the Mac. Right now it's slow, doesn't LDAP properly and because Mail accesses it every time I send email, it makes me wait after every single email I send while I wait for address book to update.
I'm almost inclined to go use Entourage if Apple doesn't fix this.