It always seemed to me like a strange place to put such a thing, much like how File Sharing management used to be a part of Workgroup Manager, instead of Server Admin. All software, though, is a work in progress, and things move around.
In Snow Leopard, NFS mounts are now configured in Disk Utility, which makes a little more sense, but is still kind of a strange place for this. Launch Disk Utility, and go to File -> NFS Mounts..., and you'll be presented with a handy-dandy little window that offers you the ability to "Edit automatic NFS mounts for this computer." Click the plus, and enter the URL and the mount point. There's two check boxes for what I'd imagine are the two most commonly-used options for NFS mounts, which are mounting read-only, and ignoring SUID privileges. There's also an Advanced Mount Options box, which appears to take the standard mount options. In fact, if you check the read-only or no SUID boxes, you'll notice that it helpfully fills in the Advanced Options box with "ro" or "nosuid", respectively.
Once you've entered the pertinent info, you have to click "Save". If you close the window, it will close with no complaint, but you won't have any NFS shares mounted. Odd UI choice, there.
A couple interesting notes:
- Shares will be mounted with the nobrowse option, i.e. they won't show up in the Finder.
- Just like how NFS mounts in Tiger went into NetInfo, when you create one, and record will be added to /Local/Default/NFS. So, if you're connected via SSH, and you're looking for NFS mounts, dscl is your friend.
- If you're looking at the URL via dscl or Workgroup Manager, you can edit the mount options by adding flags to the VFSOpts attribute. But it's probably a better idea to use Disk Utility when possible.
It might be nice to see a utility whose sole purpose is managing automounts, and not just NFS but AFP as well. But if there were one, it would probably go into /System/Library/CoreServices, and you'd have to get there through System Preferences, or something.