I am curious with current technology, what would be the most efficient way to handle building something like a Facebook wall or Google + wall/stream with PHP, Javascript, and MySQL.
This is something a lot of people try to reproduce and fail.
The goal is to have a stream of data like posts and posts can have comments and everything will auto update without reloading the page.
I know in the past some people have talked about using Comet but I have yet to see it in use really. Also now that Node.js exist, is that something that would do this job better?
Please tell me how you would do this?
Take a look into long polling and web sockets. Web sockets are only supported by modern browsers, but that may be okay with you. Long polling relies on a client making a request with a long timeout period and the server holding on to it until something happens. This alleviates the pounding required of constant polling for updates and also results in a more responsive user interface. I believe this is what Facebook uses.