Real time communications are cool, isn't it? Something impossible to do five years ago now (or almost impossible) is already available. Nowadays we have two possible solutions. WebSockets and Comet. [...] I prefer to use comet (at least now). It's not as good as websockets but pretty straightforward ant it works (even on IE). Now I'm going to explain a little script that I've got to perform a comet communications, made with PHP.