gistfile1.py

# Try and generate a unique username. Hopefully they never see this.
for count in itertools.count(1):
# Get the first part of the email and use 30 characters
    username = request.POST['email'].split('@')[0][:30]
    if not User.objects.filter(username = username).exists():
        break
    else:
    # Try and append a number in the last postion of the username
        username = username[:30-len(str(count))] + str(count)
        continue
    break