To configure the Apple Remote Desktop Agent parameters that are user-specific was harder to find, since they are stored in the NetInfo database using a very non-guessable tag naprivs (and the value is a bitmap). Luckily, after much searching, I found that there is a perl script that comes as part of the Agent package called kickstart. I found it on the "Upgrade" partition that was built on the disk image we made for the install (from Firewire) in the directory /System -> Library -> CoreServices -> ARD Agent.app -> Contents -> Resources. This script is specifically designed for this purpose and I'm quite surprised I couldn't find any mention of it during a fairly exhaustive search (macosxhints, google, macosxlabs, etc.). One example of how to use this is:
kickstart -verbose -configure -users itadmin -access -on -privs -all
There is complete usage information is given if the script is run without any arguments. If this is all in the user manual ... then this will probably only help the few other techies that like me are too stubborn to look it up, but I don't have the manual here to verify this!

