Michael Feichtinger has posted a simple websocket example to his blog today. It shows the creation of a simple "web chat" application for real-time communication without the mess that can come with ajax.

The classic example for websockets is a chat. This chat example has only 200 lines of code (excl. the Websocket class), is really easy to understand and customizable.

He creates a basic "WebsocketClass" class that (in his example) connects to an IP and port. It uses JSON as the messaging format and some basic javascript to handle the clicks of the "chat" and "login" buttons. You can see an example in action here and download the source for the server.php here.

Justin Ireland has posted an article to his blog about creating real-time interfaces for your sites using the combination of HTML, CSS and Javascript to connect to a physical interface on the backend.

Physical interfaces such as button panels or remote controls have many disadvantages. Panel controls require a dedicated display for feedback and physical access to a fixed location. IR remote controls offer only one-way communication with limited feedback and can become difficult to manage for multiple devices. [...] We propose a new type of solution to address these issues and bring simplified management and control to a broader market through embedded virtual interfaces.

He lays out the structure of the application, some of the issues that could come up in the connection (using COMET and Websockets). His proof of concept is a connection to a HDMI switch that can be talked to through an embedded controller via a simple interface.