how to open a socket in php

I am completely new to sockets and not that familiar with the concept. I am planning on making a phone application f开发者_开发问答or chatting. now I was told that if you open a socket you can push results (chat entries) to the phone application.

now is this something I can do with fsockopen php function?? and how would I keep the connection open and push data from the database to the application?

Thanks

Read this and you'll be up and running in no time. Socket servers are mysterious and fun... :D