I haven't seen anything about this in the FAQ or elsewhere, so I'll ask here:
I've just made a profile this morning. Is my pic available immediately, or is there a review period before others can see it? I looked at my profile and the photo's there, so I've assumed it's good to go, and that's why I sent out a couple of messages to people in my area. But I've also made a couple of forum posts, and my thumbnail in the thread is blank, as though I have no propic.