hey.. now much does it cost on an average to pay these sites for an observership or externship in psychiatry.Yes, it's paid service. But they are very reliable and they'll put in the specialty/state that you want.
Other than this, I don't think a web link will work for you.
The only alternative to Americlerkships is connections, your friends can help you get an observership or externship otherwise a website will never help you.