My client would like to have a form on his Web site that allows people to submit photos and have them appear on the site. He would like to be able to approve the photos before they appear - he wants the photos to appear on the page as soon as he approves them. Are there any services that you would recommend that would accomplish this?
There are lots of externally hosted services as well of course but my first thought about this was that the visitors may not always see their photos because of caching. Do make sure that your client is aware of the workings of both browser cache and proxy cache so that he doesn't blame you when one of his customers fails to click on "refresh" and then complains.