As with most things, there is no single best answer.
For the most part, however, a photograph is unnecessary and potentially even harmful for two reasons:
Most resumes are nowadays electronically scanned into a central database as part of the application process. An image attached to your resume could potentially hinder this process causing your resume to be "sidetracked" or even ignored. In this difficult job market, you cannot afford to lessen your chances that your application is reviewed and acted upon.
Next, prejudices exist and are an unescapable reality of life: let the job manager evaluate your application based on your experience and qualifications and not on cultural hangups.