In the end I created a 3x3 platform two blocks above the ground. In previous versions of minecraft if the player would look at enderman to cause them to agro, they would gather around the platform until the player killed them or re-logged.

In the pre-release and snapshots using the same setup described above the enderman will gather around the platform and soon (within a second or two) forget they are ago. The player can come out from under the platform and the enderman will not attack.