I've been looking around for an option to do this, but I can't seem to find one anywhere.

I'm looking for a way to be able to have a list of approved devices for activesync.

Some of our users have company supplied iPhones, so we want them to be able to use activesync (and hence can't turn off the mobile devices connection for them), but we would like to be able to stop them from (for example) hooking up a non company supplied iPad or Android phone.

Is there a way to limit activesync to certain device ids ?