Remember when you used to play pokemon and use the action replay to be able to walk through walls? Well my idea is for a plugin that goes with worldedit (or not), where you select a region, type down a command, and BAM only people with the permission can walk THROUGH that wall. I saw this on kuledud3's server and I really love the idea. This plugin will be ESSENTIAL to my server.
I think there have been threads like this in the past. Aside from using dark magic or some freaky-as-hell methods, the only way I know of walking through walls smoothly is with a client mod installed, be it Zombe's fly/noclip mod or a griefing client. In short, I don't think there's a way that Bukkit alone can do this.
Um, I recently donated to the server that had this. and I realized it was only a wall for the members. For the donators like myself, there was nothing there. Not even a black outline of a "clear block". If that helps at all...
sounds like worldguard with Regions where only an allowed Group may enter the Region and no others can.
I have been following this plugin idea forever it seems. http://forums.bukkit.org/threads/fake-wall.121438/page-2