The JW Player from Longtail Video is one of the best Flash based media players out there. It is very customizable; you can skin it, add extra functionality with plugins, and modify behavior using the wide array of flashvars available.
It also has a rich Javascript framework, meaning you can hook into the player as it is running, and change the state of the player.
Javascript has the ability to make things happen at different times using the setTimeout function. You can even schedule recurring events using the setInterval function. This functionality isn’t jQuery, but you can use these functions in your code to make your interfaces more user friendly.
We all love using plugins for jQuery, it cuts development time, and in most cases if you can think of an idea, someone has made a plugin for it.
Occasionally though, you need to make your own, or you simply want to make your own!