My project has a "sort by last name" requirement, but we wanted to accomodate "funky" names. Here's what I did:

There are four fields in the database:

  first_name
  last_name
  display_name
  primary_email

All 3 name fields are optional. The email address field is required, but you could use a customer ID or username if that is more appropriate for your app.

The name are never accessed directly, except on the one form where you can edit these fields. In general, they are accessed by these two helper methods:

  @property
  def name(self):
      if self.display_name:
          return self.display_name
      if self.first_name and self.last_name:
          return self.first_name + ' ' + self.last_name
      return self.primary_email

  @property
  def last_first(self):
      if self.first_name and self.last_name:
          return self.last_name + ', ' + self.first_name
      if self.display_name:
          return self.display_name
      return self.primary_email

Then we do a culture specific case insensitive sort. This should cover most cases pretty well....... I hope :-)