I have been playing around with the jQuery library for the past few days at work and I have to tell you, I am loving it more everyday.
John Resig put together a great little application in jQuery. It is fast, small (the compact version), very responsive and freakishly easy to use. Couple it with the many plugins out there and you have one excellent, speedy web development tool. And in this era of “Everything Ajax has to be golden” nothing gets you to the lofty position of web guru like a great, prebuilt and widely-supported application framework like jQuery.
If you really want to play a good bit with the application, I say you head over to the jQuery Interface Elements site. As far as plugins go, this one set of plugins will totally unleash the full power of jQuery. Plus it has some freaking cool demos.
Anyway, add this to your web development arsenal. It will certainly come in handy at some point.