Windows Server 2k3 Active Directory password retrieval question

I'm working in a win2k3 environment with xp clients. There are about 900 pc's and about 1170 domain users with various levels of authority across the domain. I was wondering what would be the best way to retrieve passwords. I have used sniffers in the past and I can easily reset the passwords, but I was wondering what would be the best way to find out what the password is. On a local machine I would just use SAMInside or boot from a live cd. I was just wondering if there's a better way than sniffing. Until now, I've just never thought about it. Any opinions or favorite methods?