AccessLevel model

models.py

class AccessLevel(models.Model):
    user = models.ForeignKey(User, related_name='access_levels')
    access_level = models.CharField(
        max_length=12,
        choices=(("open", "open"), ("closed", "closed")),
        default="open"
    )
    starts = models.DateTimeField(auto_now=True)
    expires = models.DateTimeField(blank=True, null=True)
    content_type = models.ForeignKey(ContentType, related_name='access_levels')
    object_id = models.PositiveIntegerField()
    content_object = generic.GenericForeignKey('content_type', 'object_id')

This model allows us to set any piece of content in our system to "open" or "closed" per user.
This would be the basis of an object-level permissions system.