MOSS allows you to display information from the active directory in the user profile store. However, if you want to allow write back to the AD then you need to either write your own custom code or use a tool like this one:

Bamboo solutions has a tool that seems to fit the bill. I will evaluate this very soon and update this blog post.

http://store.bamboosolutions.com/ps-45-5-user-profile-sync.aspx