Javascript (menu-)popup class for free use:
link
demo
Demonstration of AJAX (Asynchronous Javascript And XML) and PHP with a small chat - for free use:
link
demo
[UPDATE] with new version of spwChat.js library [v200703291704].
User-File-Matrix Copy in php: If you have n Users and m Files and you need a quick way to select which files copied to which users.
link
demo