Case-insensitive email with devise

gistfile1.rb

# User model

before_save :downcase_email

class << self
  def find_for_authentication(conditions)
    conditions[:email].try(:downcase!)
    super
  end

  def find_or_initialize_with_error_by(attribute, value, error=:invalid)
    value.downcase! if attribute == :email
    super
  end
end

protected

def downcase_email
  self.email.downcase!
end