You can find them in the yellow pages, or on the web. A lot of agencies have one day a week where they will take walk-ins. Take your portfolio with you. And expect them to be harsh. If you can't handle this kind of criticism, then don't go.
Some people have nothing better to do than complain.
Not yet, anyway. I do occasionally link to people's page from the related links page when someone sends me an ad or some useful information and they'd like me to link to their site. I also link to pages related to CK, models, or advertising. No, I haven't seen them. I also have seen no official announcement that they even exist.