Can anyone describe an efficient and semi-simple way of applying a whole series of permissions (view,read,post,edit,delete,etc.) that can be applied to multiple content components and allows moderators, administrators, etc. to override user-based permissions? I know I've basically asked the same question before, but I was able to get that system to work to my satisfaction at the time. Now I want something that is scalable to multiple components and isn't session based, meaning the implementation doesn't require custom sessions.

My setup involves users and groups that both could potentially have mutually exclusive permissions (a user belonging to a group could have permission to do one thing, but since he is a member of the group, he can't and vice-versa). The permission system I've devised works until I try to figure out a clean way of allowing moderators and administrators a way of overriding the user and group permissions. I think I'm almost there, I just need someone to point out a trick to doing this right. Any help would be greatly appreciated.