In the Member Photos section of the Social Networking admin page, you can choose how many photos you want to allow members to upload, customize the language, and configure the options.  As mentioned on this page, the member photos get displayed on the Public Profile page, in the Photo section,  if you have created a Photo Category and added it to your Public Profile page (just select your Public Profile page from the "Add To Page" menu on the Add/Edit Category Page). Members can manage their photos from their Edit Profile page.