There are certain jobs where your looks are a crucial factor. If you're aiming for a gig as an actor or a model, the casting director or agent will want to see your 8x10. In virtually every other situation, a photograph included with a résumé is a fatal flaw.
Here's why: employers have to be careful not to open themselves up to accusations of illegal discrimination. If you include a photo of yourself with your résumé, the employer now knows roughly how old you are; has a general idea of your ethnic background, and can see if you're attractive, overweight, or suffering from an obvious disability. To avoid the perception that they either rejected or hired you based on these attributes, many employers will simply throw away a résumé with a photo attached.