Added new "worldborder.bypass" permission which will allow a person to move around outside the border without being knocked back. This permission is not granted to anyone by default, even Ops, and is not included in the "worldborder.*" permission set.

Thanks to st-remy and guyag for pull requests close to what I ended up implementing here.

src/com/wimbli/WorldBorder/BorderCheckTask.java

@@ -46,6 +46,10 @@ public class BorderCheckTask implements Runnable
 		if (border.insideBorder(loc.getX(), loc.getZ(), Config.ShapeRound()))
 			return null;
 
+		// if player has "worldborder.bypass" permission, allow them beyond border
+		if (Config.HasPermission(player, "bypass"))
+			return null;
+
 		Location newLoc = newLocation(player, loc, border);
 
 		if (Config.whooshEffect())

src/com/wimbli/WorldBorder/Config.java

@@ -283,8 +283,6 @@ public class Config
 	{
 		if (player == null)				// console, always permitted
 			return true;
-		else if (player.isOp())			// Op, always permitted
-			return true;
 
 		if (player.hasPermission("worldborder." + request))	// built-in Bukkit superperms
 			return true;

src/plugin.yml

@@ -31,7 +31,7 @@ commands:
            /<command> debug <on/off> - turn debug mode on or off.
 permissions:
   worldborder.*:
-    description: Grants all WorldBorder permissions
+    description: Grants all WorldBorder permissions, except for bypass
     children:
       worldborder.set: true
       worldborder.radius: true
@@ -105,3 +105,6 @@ permissions:
   worldborder.dynmapmsg:
     description: Can set the label text for borders shown in DynMap
     default: op
+  worldborder.bypass:
+    description: Can go beyond the border without being knocked back
+    default: none