I've just enabled the "shoutbox" feature on my website. I think it's kinda cool. Every site should have one. :)

Anyway, my site isn't only a showcase for my and others work, but also a place for me to test new website features/widgets and stuff. I know the shoutbox isn't new, but I like the way it works. You can just add a message to the site without signing up anywhere. Plus, the shoutbox is visible on almost every page and the message sent shows up instantly. To extend the shoutbox you could add more "rooms" to it, like in a chat. By doing so the shoutbox may work well on larger sites too.

If you who reads this got any ideas you would like to see in action on a website, please tell me with a comment or PM and I might create it, showcase it on my website and (of course) share any source code. It could for example be a random welcome message showing up at the top of every page. Another example could be a logging system for database errors. That is two very easy examples, but hopefully you get the point. ;)

And btw, I use HTML, CSS, JavaScript, PHP (on server) and MySQL (for database). So really anything is possible.