Do you have to post a photo to join or use sites like Facebook or MySpace?

I want to join either or both to see whether they might be an effective way of connecting with other single people my age who have . As you might guess, I don't want to post a photo for public viewing with a profile that broadcasts the fact that I have . I have already joined three of the largest personals sites for people with , and those sites are OK. I just want to know if Facebook and MySpace are worth the effort of joining and of all of the media attention they get.