I found model definitions with large number of fields with long help_text unreadable and feel that help_text doesn't really belong to field definition. With this snippet help_text attributes can live outside field definitions in inner HelpText class so field definitions become shorter and more readable.
Usage:
    from django.db import models
    import readable_models
    class MyModel(models.Model):
        __metaclass__ = readable_models.ModelBase
        name = models.CharField('Name', max_length=30)
        address = models.CharField('Address', max_length=255)
        # ... long list of fields
        class HelpText:
            name =  'The name ...'
            address = 'Example: <very verbose example is here>'